Device for testing air leakage capability of battery cell explosion-proof valve
By using a battery cell explosion-proof valve leakage capacity testing device, the pressure change of the battery cell under thermal runaway can be monitored in real time. This solves the problem that existing technologies cannot quantitatively assess the leakage capacity of explosion-proof valves, optimizes the size design of explosion-proof valves, and improves the safety of battery cells.
Patent Information
- Application Number
- CN202520634981.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-07
- Publication Date
- 2026-01-02
- Estimated Expiration
- 2035-04-07
AI Technical Summary
Existing technology cannot quantitatively assess the venting capacity of cell explosion-proof valves, leading to unreasonable valve size design, which may affect the strength of the battery cover or result in insufficient pressure relief capacity.
Design a test device for the leakage capacity of a battery cell explosion-proof valve, including a battery cell clamping unit and a pressure monitoring unit. The battery cell is heated by a heating element and the pressure change of the battery cell under thermal runaway is monitored by a planar diaphragm or flexible thin film pressure sensor. The data obtained by the temperature monitoring unit is combined to perform simulation and optimize the design of the explosion-proof valve.
It enables real-time monitoring and quantitative evaluation of the pressure relief capacity of the cell explosion-proof valve, provides input data for the simulation model, optimizes the size design of the explosion-proof valve, and ensures the safety of the cell.
Smart Images
Figure CN223756316U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of safety test of electric core, especially to a kind of testing device of electric core explosion-proof valve gas leakage capacity. BACKGROUND
[0002] At present, the safety test technology for electric core, such as the test of the gas leakage capacity of the explosion-proof valve of electric core, is usually to fix the electric core 10 to be tested by using the clamping plate 20, and then to test its safety, wherein the two clamping plates 20 are connected by four limiting columns 30. The test method is to heat the electric core on one side by using a heating sheet, or to embed a heating sheet, so that the electric core reaches the temperature of thermal runaway, and then to observe whether the weld between the battery cover plate and the battery shell cracks, whether the pole column rises, whether the shell breaks, and the like. This research method can only visually observe the gas leakage capacity of the explosion-proof valve, whether it reaches the gas leakage capacity after the electric core loses control, and cannot quantitatively study the explosion-proof valve to better design the size of the explosion-proof valve. Figure 1 However, the design of the explosion-proof valve of the electric core needs to be quantitatively calculated, because the size of the explosion-proof valve is directly related to the safety performance of the electric core. If the size of the explosion-proof valve is too large, it may affect the strength of the battery cover plate, causing the cover plate to break, and if the size of the explosion-proof valve is too small, it may cause the pressure relief capacity of the explosion-proof valve to be insufficient, affecting the pressure and energy release of the electric core under the condition of thermal runaway.
[0003] Therefore, an equipment is needed to test the safety of the explosion-proof valve of the electric core, and to display the pressure change in the electric core in real time to monitor whether the internal pressure of the electric core can be released in time after the electric core fails.
[0004] UTILITY MODEL CONTENTS The utility model aims at overcoming the defects of the prior art, and provides a testing device of electric core explosion-proof valve gas leakage capacity.
[0005] The utility model is implemented in the following manner. A testing device of electric core explosion-proof valve gas leakage capacity comprises an electric core clamping unit, the electric core clamping unit comprises two oppositely arranged electric core clamping plates, the electric core clamping plates are connected by limiting columns, a clamping space of an electric core to be tested is formed between the two electric core clamping plates, at least one inner side surface of the electric core clamping plate is provided with a heating sheet for heating the electric core to be tested, at least one electric core clamping plate is connected with a pressure monitoring unit, and the pressure monitoring unit is used for monitoring the pressure change data of the electric core to be tested clamped and limited by the electric core clamping plate when releasing pressure under thermal runaway.
[0006]
[0007] Preferably, the pressure monitoring unit comprises at least one planar diaphragm capsule pressure sensor arranged outside one of the cell clamping plates and mounted on a sensor mounting plate.
[0008] Preferably, the cell clamping plates and the sensor mounting plate are arranged in a stack by sharing the limiting posts.
[0009] Preferably, the pressure monitoring unit comprises at least one flexible thin film pressure sensor arranged between the heating sheet / cell clamping plate and the cell to be measured.
[0010] Preferably, a temperature monitoring unit is further included for being attached to the surface of the cell to be measured to monitor the temperature value of the cell to be measured to obtain the temperature value of the cell to be measured at different time points.
[0011] Preferably, the temperature monitoring unit comprises a flexible thin film temperature sensor arranged between the flexible thin film pressure sensor and the cell to be measured.
[0012] Preferably, the flexible thin film temperature sensor and the flexible thin film pressure sensor are each two and are each located between the cell to be measured and the adjacent cell clamping plate.
[0013] Preferably, the heating sheet, the flexible thin film pressure sensor and the flexible thin film temperature sensor are rectangular.
[0014] Preferably, during measurement, the flexible thin film temperature sensor fully covers the contact surface of the cell to be measured.
[0015] Preferably, the limiting posts are four and are arranged at the four corners of the near-rectangular cell clamping plate.
[0016] The utility model discloses a heating sheet and a pressure monitoring unit are arranged, which can heat the cell to be measured, and when the cell to be measured is heated to the pressure relief of the explosion-proof valve, the pressure change of the cell to be measured during the pressure relief can be tested by the pressure monitoring unit, the pressure monitoring data of the pressure monitoring unit are used to represent (measure) the pressure in the shell in real time, so that whether the explosion-proof valve pressure relief capacity can meet the pressure relief requirement can be monitored in real time when the cell safety test cannot be evaluated, and the pressure change data during the pressure relief can be used as the input data of the simulation to design the explosion-proof valve, so that the simulation model is searched based on the simulation model, and the temperature collected by the temperature monitoring unit and the ideal gas equation are combined to calculate, the pressure change in the cell is simulated, the explosion-proof valve of the cell is optimized, the optimal size of the explosion-proof valve is found, and the problem that the explosion-proof valve pressure relief capacity cannot be evaluated and no pressure relief data can be used as the input data of the simulation when the cell safety test cannot be evaluated is solved. BRIEF DESCRIPTION OF DRAWINGS
[0017] Figure 1 is a schematic diagram of a test device for the gas release capacity of an existing battery explosion valve.
[0018] Figure 2 is a schematic diagram of a test device for the gas release capacity of a battery explosion valve according to the first embodiment of the present application.
[0019] Figure 3 is a schematic diagram of a test device for the gas release capacity of a battery explosion valve according to the second embodiment of the present application.
[0020] Figure 4 is Figure 3 is a partial enlarged schematic diagram of part A in FIG. 4.
[0021] Figure 5 is Figure 3 is a partial enlarged schematic diagram of part B in FIG. 4.
[0022] Figure 6 is a schematic diagram of the stress of the internal pressure of the battery and the tangential stress of the shell when a flexible thin film pressure sensor is used to monitor the pressure.
[0023] Figure 7 is a schematic diagram of the change of the thermal runaway pressure value after the battery triggers thermal runaway.
[0024] Figure 8 is a schematic diagram of the change of the temperature after the battery triggers thermal runaway. DETAILED DESCRIPTION
[0025] The present application will be further described below in conjunction with the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.
[0026] Referring to Figures 2 to 5 in the exemplary embodiments of the present application, the test device for the gas release capacity of a battery explosion valve includes a battery clamping unit, the battery clamping unit includes two oppositely arranged battery clamping plates, such as a first battery clamping plate 1 and a second battery clamping plate 2, the battery clamping plates are connected by a limiting column 4, a clamping space for a battery under test 100 is formed between the two battery clamping plates, at least one of the inner side surfaces of the battery clamping plates is provided with a heating sheet 5 for heating the battery under test, at least one of the battery clamping plates is connected with a pressure monitoring unit, and the pressure monitoring unit is used to monitor the pressure change data of the battery under test clamped and limited by the battery clamping plates when the battery under test releases pressure under thermal runaway.
[0027] The utility model discloses a heating piece and pressure monitoring unit are arranged, can realize to the heating of the measured battery, and when heating to its through the pressure relief of explosion -proof valve, can through the pressure monitoring unit and test the pressure change of the pressure relief of battery, can real -time monitoring that the battery safety test can not assess whether the pressure relief capacity of explosion -proof valve meets the pressure relief requirement, and can utilize the pressure change data of the pressure relief of obtaining, as the input data of analog simulation carries out the design of explosion -proof valve, is convenient for later based on simulation model, and then combines the temperature of the acquisition of temperature monitoring unit and ideal gas equation and calculates, simulates the pressure change in the battery, optimizes the explosion -proof valve of battery, finds the explosion -proof valve of optimal size, solves the problem that the battery safety test can not assess whether the pressure relief capacity of explosion -proof valve is enough and does not have any pressure relief data to be used as the input data of analog simulation.
[0028] As Figure 2 The pressure monitoring unit includes at least one flat diaphragm capsule pressure sensor 3, which is arranged on the outer side of one of the battery clamping plates and is installed on a sensor mounting plate 6. The flat diaphragm capsule pressure sensor includes a cylindrical box or cylindrical shell, which is arranged in the space between the sensor mounting plate and the adjacent battery clamping plate. In this embodiment, when the measured battery is heated to the expected pressure relief temperature by the heating piece, the pressure change of the battery shell is monitored by the flat diaphragm capsule pressure sensor, so as to obtain the required internal pressure change data of the battery.
[0029] It should be noted that when using a flat diaphragm capsule pressure sensor, if the elastic coefficient of the flat diaphragm capsule pressure sensor is too small, the shell deformation will be large, the extrusion force of the flat diaphragm capsule pressure sensor will be affected by the tangential force, and not all of the extrusion force can be reflected as the pressure in the shell. Therefore, the greater the elastic coefficient of the flat diaphragm capsule pressure sensor, the higher the test accuracy, and the closer the display value of the flat diaphragm capsule pressure sensor to the pressure in the shell. In addition, since the test result of the flat diaphragm capsule pressure sensor does not represent the value of the internal pressure of the battery, and the internal pressure of the battery and the reaction change of the system cannot be directly analyzed, when using the flat diaphragm capsule pressure sensor for measurement, the trend of pressure change and the relative size of multiple test results can be used to compare and analyze the internal pressure of the battery.
[0030] In the example embodiment, the heating piece 5 is one, and of course, two can also be provided.
[0031] The test device for the explosion -proof valve pressure relief capacity of battery shown in Figure 2 When the battery heat runaway pressure test is performed by using the test device for the explosion -proof valve pressure relief capacity of battery shown in the figure, the external heating piece is used to heat the measured battery to cause heat runaway. The internal pressure of the battery is evaluated by using the values collected by the flat diaphragm capsule pressure sensor. After testing by using the flat diaphragm capsule pressure sensor, if the pressure change of the battery is not obvious, it indicates that the battery is in a stable state, and the battery is not in a heat runaway state.Figure 7 As shown, according to the opening pressure of the explosion-proof valve of the battery cell, it can be concluded that the maximum value of the planar diaphragm capsule pressure sensor should be 0.8 MPa*84 mm*205 mm, which is converted to 13.8 KN, and the actual pressure value is about 4.5 KN, so it can be seen that the value monitored by the planar diaphragm capsule pressure sensor can only represent the trend of the pressure inside the battery cell, not the actual measured value.
[0032] From Figure 7 It can also be seen that after triggering the heat runaway gas opening valve, the internal gas pressure of the battery cell still rises under the shell leakage state. After consulting the data, it is found that the first large amount of gas failure is due to the collapse of SEI structure, decomposition, large amount of gas and electrolyte decomposition gas. The second large amount of gas is due to the temperature reaching the decomposition temperature of the positive electrode material (the critical temperature of the stable state of the ternary material is 400°C), and from Figure 8 It can be seen from
[0033] In the example embodiment, the battery cell clamping plate and the sensor mounting plate 6 are arranged by stacking through the common limiting column 4. In the example embodiment, the limiting column is four, arranged at the four corners of the nearly rectangular battery cell clamping plate, and the axes of the four limiting columns are connected end to end to form a rectangle.
[0034] In the example embodiment, the pressure monitoring unit includes at least one flexible thin film pressure sensor 7, which is arranged between the heating sheet / battery cell clamping plate and the battery cell to be tested (if there is only one heating sheet, it is arranged between one battery cell clamping plate and the battery cell to be tested). By using the flexible thin film pressure sensor 7, the displacement of the battery cell to be tested can be fixed directly by the limiting column, and the battery cell shell has no deformation amount, as shown in Figure 6 Figure 6 For the flexible thin film pressure sensor measurement, the stress state diagram of the battery cell shell can be seen, and the battery cell shell has no shell tangential force when it is stressed, and the value displayed by the flexible thin film pressure sensor is equal to the internal pressure value of the shell. Compared with the planar diaphragm capsule pressure sensor test, the internal pressure of the battery cell can be directly obtained, without data conversion processing, and the obtained data can be directly used to analyze the real change of the internal pressure of the battery cell and judge that the pressure relief capacity of the explosion-proof valve meets the battery cell to be tested.
[0035] In the example embodiment, a temperature monitoring unit is further included, which is attached to the surface of the battery cell to be measured to monitor the temperature value of the battery cell to be measured and obtain the temperature value of the battery cell to be measured at different time points.
[0036] In the example embodiment, the temperature monitoring unit includes a flexible film temperature sensor 8 arranged between the flexible film pressure sensor and the battery cell to be measured.
[0037] In the example embodiment, the flexible film temperature sensor and the flexible film pressure sensor are each two and are each located between the battery cell to be measured and the adjacent cell clamping plate.
[0038] By using the flexible film temperature sensor and the flexible film pressure sensor, the temperature and pressure at different positions of the battery cell to be measured can be measured together, and then the ideal gas equation can be used to calculate the pressure state inside the battery cell.
[0039] In the example embodiment, the heating sheet, the flexible film pressure sensor and the flexible film temperature sensor are rectangular in shape, and the size is adapted to the battery cell to be measured.
[0040] The test device for the discharge capacity of the battery cell explosion-proof valve can detect the change of the internal gas pressure of the battery cell without testing the internal gas pressure of the battery cell through the built-in sensor or other methods, so as to explore the process of thermal runaway of the battery cell material through the change of the gas pressure.
[0041] The basic principle and main features of the present application and the advantages of the present application are shown and described above. It is obvious for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or basic characteristics of the present application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application.
[0042] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description manner of the specification is only for the sake of clarity, those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.
Claims
1. A device for testing the venting capacity of an explosion relief valve of a battery cell, characterized in that The battery cell clamping unit comprises two oppositely arranged battery cell clamping plates connected by a limiting column, a clamping space for a battery cell to be tested is formed between the two battery cell clamping plates, the inner side surface of at least one of the battery cell clamping plates is provided with a heating sheet for heating the battery cell to be tested, at least one of the battery cell clamping plates is connected with a pressure monitoring unit for monitoring the pressure change data of the battery cell to be tested clamped by the battery cell clamping plate when the battery cell to be tested is pressure released under thermal runaway.
2. The device of claim 1, wherein, The pressure monitoring unit comprises at least one planar diaphragm capsule pressure sensor arranged on the outside of one of the battery cell clamping plates and mounted on a sensor mounting plate.
3. The testing device for the leakage capacity of the cell explosion-proof valve according to claim 2, characterized in that, The battery cell clamping plate and the sensor mounting plate are arranged in a stacked manner by a common limiting column.
4. The testing device for the leakage capacity of the cell explosion-proof valve according to claim 1, characterized in that, The pressure monitoring unit comprises at least one flexible thin film pressure sensor arranged between the heating sheet / battery cell clamping plate and the battery cell to be tested.
5. The testing device for the leakage capacity of the cell explosion-proof valve according to claim 4, characterized in that, A temperature monitoring unit is further included for being attached to the surface of the battery cell to be tested to monitor the temperature value of the battery cell to be tested and obtain the temperature value of the battery cell to be tested at different time points.
6. The device of claim 5, wherein the device is configured to measure the pressure decay rate of the vent valve of the battery cell. The temperature monitoring unit comprises a flexible thin film temperature sensor arranged between the flexible thin film pressure sensor and the battery cell to be tested.
7. The device of claim 6, wherein the device is configured to measure the pressure decay rate of the vent valve of the battery cell. The flexible thin film temperature sensor and the flexible thin film pressure sensor are each two and are each located between the battery cell to be tested and the adjacent battery cell clamping plate.
8. The device of claim 6, wherein the device is configured to measure the pressure relief capability of the explosion relief valve of the battery cell by measuring the pressure relief capability of the explosion relief valve of the battery cell at a temperature of 20°C and a relative humidity of 10%. The heating sheet, the flexible thin film pressure sensor and the flexible thin film temperature sensor are rectangular.
9. The device of claim 6, wherein the device further comprises a pressure source. During measurement, the flexible thin film temperature sensor fully covers the contact surface of the battery cell to be tested.
10. The device of claim 1, wherein, The limiting column is four, and the four corners of the nearly rectangular battery cell clamping plate are arranged.