Equipment and methods for withstand voltage and burst testing of high-energy-density, long-cycle cylindrical battery cell casings

Abstract

This invention discloses a device and method for testing the withstand pressure and burst resistance of high-energy-density, long-cycle cylindrical battery cell casings. The device includes: a water supply unit comprising a water tank, a filter, and a liquid booster pump connected in sequence; a pneumatic control unit comprising a compressed air source, an electro-proportional valve, and a pneumatic solenoid valve; a high-pressure delivery circuit connected to the output end of the liquid booster pump, on which a first pressure sensor, a safety valve, and a liquid high-pressure main solenoid valve are sequentially arranged; a multi-station testing terminal comprising multiple liquid high-pressure branch solenoid valves connected in parallel to the rear end of the liquid high-pressure main solenoid valve, each branch solenoid valve corresponding to a battery cell casing station under test; and a control system comprising a PLC controller and a human-machine interface. The PLC controller electrically controls the electro-proportional valve, the pneumatic solenoid valve, the liquid high-pressure solenoid valve, and the liquid high-pressure circuit solenoid valve according to the parameter instructions set in the human-machine interface, and acquires the signal from the first pressure sensor in real time.

Description

Technical Field

[0001] This invention relates to the technical field of mechanical properties and safety reliability testing of cylindrical battery casings, and particularly to a device and method for testing the withstand voltage and burst resistance of high-energy-density, long-cycle cylindrical battery casings. Background Technology

[0002] With the increasing global demand for high-energy-density and long-cycle-life batteries, high-energy-density, long-cycle cylindrical cells have become an important battery type for electric vehicles, portable devices, and energy storage systems. These cells typically employ advanced materials and technologies, such as high-nickel cathodes, lithium metal, or silicon-carbon anodes, to improve battery energy density. However, with the increase in energy density, the safety challenges these batteries face during use are also becoming increasingly severe.

[0003] High-energy-density battery cells undergo significant volume expansion and contraction during charging and discharging, especially when the negative electrode uses lithium metal or silicon-carbon materials. This process leads to fluctuations in internal battery pressure, and after prolonged use, phenomena such as gas generation and thermal runaway may occur, affecting the battery's safety and stability. Specifically, electrolyte decomposition, oxygen release reactions of high-voltage positive electrode materials, and side reactions on the negative electrode surface can all cause gas accumulation, resulting in increased internal battery pressure. If this pressure exceeds the cell's casing's tolerance, it may cause structural failure, casing rupture, or even explosion, leading to serious safety hazards.

[0004] Existing cell casing pressure resistance testing methods, while capable of providing a preliminary assessment of the casing's static strength, often fail to effectively evaluate the long-term safety of batteries under high energy density operating conditions due to their lack of ability to cope with rapidly changing pressures. Traditional testing methods, such as hydraulic testing and gas pressure testing, can test the pressure resistance of the battery casing, but their accuracy and reliability are often limited when facing high pressure and rapidly changing internal and external pressures.

[0005] Furthermore, existing withstand voltage testing equipment is complex to operate under high-pressure conditions, often relying on manual adjustments and real-time monitoring, resulting in low testing efficiency and certain errors in data acquisition and analysis. This not only increases the difficulty of quality control during battery production but also affects the authenticity and comparability of test data.

[0006] Therefore, for high-energy-density, long-cycle-life battery cells, there is an urgent need for a new testing method that can accurately test the voltage withstand performance of the cell casing under varying operating conditions. This method should be automated, digitalized, and precise, capable of efficiently completing multiple testing tasks in a short time, ensuring that the strength, sealing, and safety of the cell casing meet the requirements of practical applications, thereby guaranteeing the safe use of high-energy-density batteries.

[0007] Based on this background, the present invention proposes a design method for withstand voltage testing of high specific energy long-cycle cylindrical battery cell casing. This method can improve testing accuracy, simplify operation procedures, reduce production costs, and achieve comprehensive monitoring and optimization of the withstand voltage performance of the battery cell casing. Summary of the Invention

[0008] To address the problems of large pressure impact, low control precision, poor pressure holding stability, and inability to simultaneously achieve independent efficiency across multiple stations in existing cylindrical battery cell casing withstand voltage testing, this invention provides a high-energy-density, long-cycle cylindrical battery cell casing withstand voltage and burst testing equipment and method. This invention solves the technical pain points of pressure overshoot and inaccurate data acquisition under high-pressure testing environments through hydraulic-pneumatic linkage control and refined segmented pressurization logic.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A high-energy-density, long-cycle cylindrical battery cell casing withstand voltage and burst testing device, the device comprising: The water supply unit includes a water tank, a filter, and a liquid booster pump connected in sequence; the filter is arranged in front of the inlet of the liquid booster pump. The pneumatic control unit includes a compressed air source, an electro-proportional valve, and a pneumatic solenoid valve; the electro-proportional valve is connected to the output end of the compressed air source and is used to adjust the driving air pressure to control the output pressure of the liquid booster pump. High-pressure delivery circuit: connected to the output end of the liquid booster pump, on which a first pressure sensor, a safety valve and a liquid high-pressure main solenoid valve are sequentially installed; Multi-station test terminal: includes multiple high-pressure liquid branch solenoid valves connected in parallel to the rear end of the main high-pressure liquid solenoid valve, each branch solenoid valve corresponding to a cell housing station under test; Control system: includes a PLC controller and a human-machine interface; the PLC controller electrically connects the electric proportional valve, pneumatic solenoid valve, liquid high-pressure solenoid valve and liquid high-pressure circuit solenoid valve according to the parameter instructions set by the human-machine interface, and collects the signal of the first pressure sensor in real time.

[0010] Preferably, the compressed air source operates at a pressure range of 0.3 MPa to 0.7 MPa. The electro-proportional valve precisely adjusts the air source pressure according to the analog signal output from the PLC, thereby achieving linear pressure increase in the hydraulic output.

[0011] Preferably, each of the liquid high-pressure branch solenoid valves is independently equipped with a second pressure sensor at its rear end; the second pressure sensor is electrically connected to the PLC controller and is used to provide feedback on the real-time pressure value of the battery cell housing at each station during the pressure holding stage.

[0012] Preferably, the filter is a multi-stage filtering structure for removing solid particle impurities in the water source and protecting the sealing performance of the one-way valve of the liquid booster pump and the high-pressure solenoid valve.

[0013] Preferably, the safety valve is a mechanical popping-type overflow valve, and the set opening pressure value is 1.1 to 1.2 times the maximum working pressure of the system.

[0014] The proportional electro-pneumatic valve is used to precisely regulate the compressed air, which serves as the power source to drive the liquid booster pump to achieve linear control of the hydraulic output. Meanwhile, by setting a high-pressure main solenoid valve for the liquid in the main circuit and parallel-connected branch solenoid valves with independent pressure sensors at each test end, a double-layer monitoring system of "main control + branch control" is constructed.

[0015] A method for testing the shell pressure resistance using the above test equipment includes the following steps: S1. Set the target test pressure value P0, the pressure holding time T1, and the pressure compensation error threshold ΔP through the human-machine interface; S2. The PLC controls the proportional electro-pneumatic valve to quickly increase the opening degree, driving the liquid booster pump to increase the liquid pressure to the preset pressure P1 in the first stage, where P1 is 70% of the target test pressure P0; S3. After the pressure reaches P1, the system enters the pause stage and maintains for 2 to 3 seconds to eliminate pipeline expansion and fluid impact; S4. The PLC controls the proportional electro-pneumatic valve to slowly increase the pressure at a preset step slope, making the test pressure smoothly approach and finally reach the target value P0; [[ID=!18]] S5. During the pressure holding time T1, the PLC monitors the data of the pressure sensor in real time; if the pressure drop value exceeds ΔP, the system automatically fine-tunes the proportional electro-pneumatic valve for pressure compensation; meanwhile, the human-machine interface displays the pressure-time curve of the pressure holding process in real time; S6. After the test is completed, close the branch solenoid valve, and the system automatically stores the test results.

[0016] Preferably, in step S2, the rapid pressure increase rate is achieved by the PLC controller adjusting the opening degree of the proportional electro-pneumatic valve, and the pressure increase rate is set to 1.0 MPa / s to 5.0 MPa / s; in step S4, the pressure increase rate is set to 0.1 MPa / s to 0.5 MPa / s.

[0017] Preferably, the dynamic compensation pressure holding logic in step S5 is: when the real-time pressure P detected by the second pressure sensor real < P0 - ΔP, the PLC commands the proportional electro-pneumatic valve to perform pressure increase adjustment in steps less than 1% of the rated pressure until P real returns to the range of P0. [[ID=3!3]]

[0018] During the pressure holding process in step S5, the PLC controller synchronously collects data from the second pressure sensors of multiple test stations and compares the pressure curves of each station in real time. If the pressure drop at a certain station is abnormal and cannot be restored by pressure replenishment, the system automatically closes the solenoid valve of the high-pressure liquid branch corresponding to that station and generates a defective product record for that station, without affecting the continued testing of other stations.

[0019] The step S6 is followed by a data processing step: the system converts the pressure-time curve into a digital report and automatically calculates the standard deviation of the pressure fluctuation as a basis for evaluating the stability of the cell casing material.

[0020] A five-stage control strategy is adopted, consisting of "rapid pressurization - stable dwell - slow and precise pressurization - dynamic pressure compensation". After the pressure reaches 70% of the target value (first stage), a 2-3 second buffer period is set, and then the pressurization rate is switched to low speed, which effectively avoids the impact of fluid shock on the test results.

[0021] A method for performing a casing burst test using the aforementioned equipment includes the following steps: S11. Set the target value of the expected burst pressure P. max This value is set to exceed the rated withstand capacity of the casing of the battery cell under test; S12. Start the segmented pressurization logic, first drive the system to boost the voltage to the standard withstand pressure point of the cell casing; S13. Entering the continuous pressure increase stage, the PLC controls the pressure to rise continuously through the electric proportional valve until the casing of the battery cell under test is physically damaged. S14. When the pressure sensor detects a sudden drop in pressure value and the drop slope exceeds the set threshold, the PLC determines that an explosion has occurred and instantly records the pressure peak value at that moment as the explosion pressure value. S15. The system immediately shuts off the high-pressure main solenoid valve and triggers an alarm, automatically saving the entire burst pressure curve.

[0022] Preferably, in step S12, the critical point for segmented pressurization is set to 80%-90% of the rated withstand voltage of the battery cell casing; after reaching this critical point, the system automatically switches to a constant low-flow pressurization mode.

[0023] Preferably, in step S14, the characteristic conditions for determining that an explosion has occurred include: the rate of change of pressure drop |ΔP / Δt| exceeds a preset threshold M; and at the same time as the pressure drops, the driving air pressure of the liquid booster pump is in a state of continuous output or increase. The above dual criteria are used to eliminate misjudgments caused by system leakage or pump stoppage.

[0024] Preferably, in step S15, while recording the burst pressure value, the system also simultaneously records the cumulative time from the start of pressurization to the occurrence of burst and the total amount of liquid injected, which is used to analyze the volume expansion rate and ductility index of the shell.

[0025] It adopts segmented continuous pressurization logic and accurately captures the instantaneous peak value of physical damage to the shell by monitoring the coupling relationship between the pressure change rate |ΔP / Δt| and the driving force state, so as to realize fully automatic explosion judgment and safe shutdown.

[0026] The beneficial effects of this invention are: 1. This invention achieves smooth switching of the boost rate (from rapid boost to fine boost of 0.1-0.5MPa / s) through closed-loop feedback between the electro-proportional valve and the PLC, eliminating pressure shocks and ensuring that the test data can truly reflect the mechanical limits of the shell material.

[0027] 2. The testing equipment in this invention has independent control function for multiple branches. During the pressure holding stage, the system can perform independent dynamic pressure replenishment for each branch; if leakage or explosion occurs at a certain station, the system can automatically shut down that branch without affecting the normal testing of other stations, greatly improving the efficiency of batch testing.

[0028] 3. By setting up a multi-stage filter at the front end of the booster pump, this invention effectively avoids the wear of water source impurities on the sealing surfaces of the one-way valve and solenoid valve, thus extending the service life of the equipment under high pressure.

[0029] 4. This invention features a triple protection mechanism consisting of a mechanical safety valve, a system relief valve, and software overpressure protection; combined with an instantaneous automatic shut-off function in the event of an explosion, it maximizes the safety of operators and equipment.

[0030] 5. The device of this invention can generate pressure-time curves in real time during testing and automatically calculate key indicators such as volume expansion rate and burst peak value, providing data support for the improvement of casing materials for high-energy-density cells. Attached Figure Description

[0031] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0032] Figure 1 The logic control diagram for the withstand voltage testing equipment; Figure 2 This is a schematic diagram of the withstand voltage testing equipment. Figure 3Monitoring the pressure curve of the withstand pressure testing equipment Figure 1 ; Figure 4 Monitoring the pressure curve of the withstand pressure testing equipment Figure 2 ; Figure 5 This is a structural schematic diagram of the tooling fixture; Figure 6 This is a schematic diagram of the operation of a high-pressure solenoid valve in a tooling fixture.

[0033] In the diagram, 1. Base plate; 2. Clamping shaft; 21. Moving shaft; 22. Clamping block; 3. Test mounting base; 31. Gas-liquid guide channel; 4. High-pressure solenoid valve; 41. Mounting groove; 42. Connector; 421. Guide slope; 5. Housing of the battery cell under test; 61. First positioning component; 62. Second positioning component; 63. Connecting rod; 7. Handle; 71. Grip section; 72. Connecting section; 81. First pivot shaft; 82. Second pivot shaft; 83. Third pivot shaft; 9. Linear bearing. Detailed Implementation

[0034] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0035] Example 1: The high-energy-density cylindrical cell casing withstand voltage testing equipment of this example has the following structural connection: Hydraulic power source section: The water source is stored in a water tank, and the outlet end is connected in sequence to a filter (for removing solid impurities) and a liquid booster pump. The liquid booster pump is a pneumatic-hydraulic linkage pump, and its output pressure is controlled by the air pressure at the drive end, i.e., the liquid source in the tooling fixture.

[0036] Control power section: A compressed air source outputs air pressure of 0.3-0.7 MPa, connected to an electro-proportional valve. The electro-proportional valve is electrically connected to the PLC control system, used to convert analog signals into precise pressure-regulated air signals. The pressure-regulated air signal drives a liquid booster pump to reciprocate through a pneumatic solenoid valve.

[0037] Monitoring and protection circuit: The first pressure sensor, safety valve (with the opening pressure set to 1.1 times the rated pressure of the system) and liquid high pressure main solenoid valve are integrated sequentially on the high pressure output line of the liquid booster pump.

[0038] Test terminal and branch control: The main high-pressure liquid solenoid valve is connected in parallel to four branches via a manifold. Each branch is equipped with a high-pressure liquid branch solenoid valve (1, 2, 3, 4). Each branch solenoid valve is independently equipped with a branch pressure sensor and a high-pressure quick connector at its rear end for connecting to the cylindrical cell under test.

[0039] Shell pressure resistance test mode: Taking a target test pressure of P0=15MPa and a holding time of T=30s as an example, the specific operation logic is as follows: S1. Parameter setting: The user inputs the target value of 15MPa and the error threshold of ±0.1MPa on the human-machine interface.

[0040] S2, Segmented Pressurization - Rapid Section: The PLC-controlled proportional valve rapidly increases the output, driving the liquid booster pump. At this time, the main solenoid valve and branch solenoid valves are fully open, and the pressure quickly rises to 10.5MPa (70% of the target pressure) in a short time.

[0041] S3, Buffer Hold: The system stops pressurizing at 10.5 MPa and maintains it for 2-3 seconds. This step aims to eliminate the elastic deformation error of the pipeline under instantaneous high pressure and to stabilize the liquid flow, preventing pressure "overshoot" caused by directly pressurizing to the set value.

[0042] S4, Segmented Pressurization - Precision Segment: After the pause ends, the PLC instructs the electro-proportional valve to slowly adjust the pressure at a smooth slope of 0.2 MPa / s until the pressure sensor feedback value accurately reaches 15 MPa.

[0043] S5. Intelligent Pressure Replenishment and Holding: During the 30-second pressure holding period, if the branch pressure sensor detects a pressure drop to 14.8 MPa (exceeding the error threshold), the PLC immediately triggers the electro-proportional valve to replenish the pressure, restoring it to 15 MPa in real time. Simultaneously, the HMI displays the pressure curves for each workstation in real time.

[0044] S6. After the test is completed, close the branch high-pressure liquid solenoid valve on the tooling fixture, and the system will automatically store the test results.

[0045] Shell burst test mode: used to determine the physical breaking pressure limit of the shell.

[0046] S11. Set the target value for expected burst pressure: Set the burst target value to 40 MPa in the HMI.

[0047] S12. Start segmented pressurization logic: The system adopts segmented pressurization logic, quickly crosses the rated pressure range, and then enters a constant speed continuous pressurization state.

[0048] S13. Entering the continuous pressurization stage, the burst point is automatically determined: The PLC monitors the pressure data at a sampling rate of 100 Hz. When the branch pressure drops instantly from 38.5 MPa to below 10 MPa (while the drive air source is still outputting), the PLC determines that moment as the burst point.

[0049] S14. Protection and Lock-up: Upon determining the instant of explosion, the PLC immediately closes the pneumatic solenoid valve and the liquid high-pressure main solenoid valve, stopping power output.

[0050] S15. Result storage: The system automatically records the peak pressure of 38.5 MPa as the burst value of the sample and exports the pressure-time curve.

[0051] Each branch circuit uses a fixture to limit and install the casing of the battery cell under test, specifically including a base plate 1, a clamping shaft 2 mounted on the base plate 1, and a test mounting base 3. A high-pressure solenoid valve 4 is provided on the side of the test mounting base 3 facing the clamping shaft 2. The high-pressure solenoid valve 4 has a mounting groove 41 on the side facing the clamping shaft 2. The mounting groove 41 is annular and is used to insert the open end of the casing 5 of the battery cell under test. The casing 5 of the battery cell under test is securely clamped between the high-pressure solenoid valve 4 and the clamping shaft 2. The high-pressure solenoid valve 4 is used to control the injection of liquid from a liquid source and a gas source (not shown in the figure) into the casing 5 of the battery cell for testing.

[0052] The base plate 1 is provided with an upwardly extending first positioning member 61 and a second positioning member 62. A handle 7 is connected to the first positioning member 61. The handle 7 includes a gripping section 71 and a connecting section 72. The gripping section 71 and the connecting section 72 form a certain angle. The connecting section 72 is horizontally positioned. One end of the connecting section 72 is pivotally connected to the first positioning member 61 via a first pivot shaft 81. The other end of the connecting section 72 is connected to the end of the clamping shaft 2 away from the test mounting base via a connecting rod 63. One end of the connecting rod 63 is pivotally connected to the connecting section 72 via a second pivot shaft 82. The other end of the connecting rod 63 is pivotally connected to the clamping shaft 2 via a third pivot shaft 83. A linear bearing 9 is provided on the second positioning member 62. After the clamping shaft 2 passes through the linear bearing 9, it maintains stable axial movement, realizing the axial movement of the clamping shaft 2 to clamp or release the battery cell housing 5.

[0053] A gas-liquid flow channel 31 is provided inside the test mounting base 3. One end of the gas-liquid flow channel 31 is connected to the liquid source and the gas source, and the other end is connected to the liquid inlet of the high-pressure solenoid valve 4. The liquid and gas are sequentially transported to the cell housing 5 through the gas-liquid flow channel 31 and the high-pressure solenoid valve 4. Flow sensors and pressure sensors can be installed on the gas-liquid flow channel 31 and / or the high-pressure solenoid valve 4 to monitor the gas flow and pressure of the liquid injection machine in real time, ensuring the safety and stability of the liquid injection process.

[0054] The clamping shaft 2 includes a movable shaft 21 and a clamping block 22 located at the end of the shaft. The clamping block 22 is detachably connected to the movable shaft 21 to accommodate battery cell housings 5 ​​of different sizes. A sealing gasket is provided at the bottom of the mounting groove 41. The connector 42 of the high-pressure solenoid valve 4 extends into the battery cell housing 5 under test, and a guide slope 421 is provided on its outer end face to ensure precise positioning of the battery cell housing 5 and to guarantee liquid injection sealing. The high-pressure solenoid valve 4 can be a normally closed direct-acting, pilot-operated, or proportional solenoid valve to meet different liquid injection pressure and flow rate requirements.

[0055] During use, the operator holds handle 7, which, along with connecting rod 63, drives the clamping shaft 2 to move axially, inserting the battery cell housing 5 under test into the mounting slot 41 and securing it. Then, the high-pressure solenoid valve 4 is opened, injecting liquid into the battery cell housing 5 from both liquid and gas sources. Flow and pressure sensors monitor the liquid injection status in real time. Once the test is complete, the handle 7 is released to remove the battery cell.

[0056] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A device for testing the withstand voltage and burst resistance of a high-energy-density, long-cycle cylindrical battery cell casing, characterized in that, The device includes: The water supply unit includes a water tank, a filter, and a liquid booster pump connected in sequence; the filter is arranged in front of the inlet of the liquid booster pump. The pneumatic control unit includes a compressed air source, an electro-proportional valve, and a pneumatic solenoid valve; the electro-proportional valve is connected to the output end of the compressed air source and is used to adjust the driving air pressure to control the output pressure of the liquid booster pump. High-pressure delivery circuit: connected to the output end of the liquid booster pump, on which a first pressure sensor, a safety valve and a liquid high-pressure main solenoid valve are sequentially installed; Multi-station test terminal: includes multiple high-pressure liquid branch solenoid valves connected in parallel to the rear end of the main high-pressure liquid solenoid valve, each branch solenoid valve corresponding to a cell housing station under test; Control system: includes a PLC controller and a human-machine interface; the PLC controller electrically connects the electric proportional valve, pneumatic solenoid valve, liquid high-pressure solenoid valve and liquid high-pressure circuit solenoid valve according to the parameter instructions set by the human-machine interface, and collects the signal of the first pressure sensor in real time.

2. The testing equipment according to claim 1, characterized in that, The operating pressure range of the compressed air source is 0.3 MPa to 0.7 MPa.

3. The testing equipment according to claim 1, characterized in that, Each of the liquid high-pressure branch solenoid valves is independently equipped with a second pressure sensor at its rear end; the second pressure sensor is electrically connected to the PLC controller and is used to provide feedback on the real-time pressure value of the battery cell housing at each station during the pressure holding stage.

4. The testing equipment according to claim 1, characterized in that, The safety valve is a mechanically activated relief valve, and its set opening pressure is 1.1 to 1.2 times the system's maximum working pressure.

5. A method for performing a casing pressure resistance test using the test equipment described in any one of claims 1-4, characterized in that, Includes the following steps: S1. Set the target test pressure value P0, pressure holding time T1 and pressure compensation error threshold ΔP through the human-machine interface; S2, the PLC controls the electric proportional valve to rapidly increase its opening, driving the liquid booster pump to raise the liquid pressure to the first stage preset pressure P1, where P1 is 70% of the target test pressure P0; S3. After the pressure reaches P1, the system enters a dwell phase and remains there for 2 to 3 seconds. S4, PLC controls the electric proportional valve to slowly increase the pressure at a preset step slope, so that the test pressure smoothly approaches and eventually reaches the target value P0; S5. During the pressure holding time T1, the PLC monitors the pressure sensor data in real time; if the pressure drop exceeds ΔP, the system automatically adjusts the electro-proportional valve to compensate for the pressure drop; at the same time, the human-machine interface displays the pressure-time curve of the pressure holding process in real time. S6. After the test is completed, close the branch solenoid valve and the system will automatically store the test results.

6. The casing pressure resistance test method according to claim 1, characterized in that, In step S2, the rapid pressure increase rate is achieved by adjusting the opening of the electro-proportional valve through the PLC controller, and the pressure increase rate is set to 1.0 MPa / s to 5.0 MPa / s; in step S4, the pressure increase rate is set to 0.1 MPa / s to 0.5 MPa / s.

7. The casing pressure resistance test method according to claim 1, characterized in that, The dynamic compensation pressure-holding logic in step S5 is as follows: When the real-time pressure P detected by the second pressure sensor real < P0 - ΔP, the PLC commands the electro-hydraulic proportional valve to increase the pressure in steps less than 1% of the rated pressure until P real returns to the range of P0.

8. A method for performing a casing burst test using the equipment described in any one of claims 1-4, characterized in that, Includes the following steps: S11. Set the target value of the expected burst pressure P. max This value is set to exceed the rated withstand capacity of the casing of the battery cell under test; S12. Start the segmented pressurization logic, first drive the system to boost the voltage to the standard withstand pressure point of the cell casing; S13. Entering the continuous pressure increase stage, the PLC controls the pressure to rise continuously through the electric proportional valve until the casing of the battery cell under test is physically damaged. S14. When the pressure sensor detects a sudden drop in pressure value and the drop slope exceeds the set threshold, the PLC determines that an explosion has occurred and instantly records the pressure peak value at that moment as the explosion pressure value. S15. The system immediately shuts off the high-pressure main solenoid valve and triggers an alarm, automatically saving the entire burst pressure curve.

9. The shell burst test method according to claim 8, characterized in that, In step S12, the critical point for segmented pressurization is set to 80%-90% of the rated withstand voltage of the battery cell casing; after reaching this critical point, the system automatically switches to constant low-flow pressurization mode.

10. The shell burst test method according to claim 8, characterized in that, In step S14, the characteristic conditions for determining that an explosion has occurred include: the rate of change of pressure drop |ΔP / Δt| exceeds a preset threshold M; and at the same time as the pressure drops, the driving air pressure of the liquid booster pump is in a state of continuous output or increase.

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