Device capable of measuring detonation critical point of battery cell failure ejected gas
By designing a device containing gas collection and testing mechanism, the problem of insufficient explosion-proof design detection and gas analysis of the battery cell is solved, and the simulation of the battery cell failure state and the measurement of the gas explosion-ignition critical point are realized, which improves the battery cell safety and testing accuracy.
Patent Information
- Application Number
- CN202422045284.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-22
- Publication Date
- 2025-08-26
- Estimated Expiration
- 2034-08-22
AI Technical Summary
The prior art lacks the test conditions for the explosion-proof design of the battery cell, and cannot detect the pressure relief effect after the explosion-proof valve is opened. The gas collection and analysis after the battery cell fails, and it is impossible to simulate the real state of the battery cell in the system. The flammable and explosiveness of the sprayed gas has not been tested.
A device including a gas collector, a battery cell fixing mechanism, an elbow clip, a gas collection and testing mechanism, an oxygen filling mechanism and a non-combustible gas filling mechanism are designed. The gas flow rate is measured through an orifice flowmeter, and the battery cell state is monitored using a temperature sensor and a pressure sensor to simulate the battery cell failure state in the PACK and test the gas explosion critical point.
The rationality detection of the explosion-proof valve design is achieved, and the PACK exhaust capacity and cooling capacity after failure is tested, ensuring sealing, accurately measuring the gas flow rate and composition, preventing secondary failure, and reducing the gas temperature to reduce the risk of explosion.
Smart Images
Figure CN223272164U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of lithium ion battery manufacturing, and particularly relates to a device capable of measuring the critical point of explosion of gas ejected from a failed battery cell. Background Art
[0002] In order to ensure the safety of lithium-ion batteries, the battery cells need to be tested. Traditional battery cell testing has the following disadvantages: (1) There are currently no test conditions that provide a basis for the design of battery cell explosion-proof dimensions. The test can only be carried out on the actual battery cell by processing an explosion-proof valve, and the pressure relief effect after the explosion-proof valve is opened cannot be detected through data; (2) After the battery cell fails, there is no collection device for the ejected gas, and the collected gas is not analyzed for temperature, flow rate, air pressure, composition, etc.; (3) After the battery cell fails, it is impossible to simulate the actual state in the system. Currently, actual sales experiments are carried out in a larger temperature chamber. In order to pursue endurance and thus increase the energy density of the system, the actual space of the battery cell in the system is limited, or the remaining space is irregular, so the test conditions are quite different from the actual temperature chamber space; (4) After the battery cell fails, the ejected gas is flammable and explosive, but the ejected gas as a combustible agent requires an oxidant to reach a certain mixed concentration, and the appropriate ratio is required for deflagration or explosion to occur. This concentration and ratio need to be tested, and there is currently no way to test it. Utility Model Content
[0003] The purpose of the utility model is to provide a device that can measure the critical point of explosion of gas ejected from a failed battery cell, so as to solve the problems existing in the background technology.
[0004] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: including a gas collector, a battery cell fixing mechanism, an elbow clamp, a gas collection and testing mechanism, an oxygen filling mechanism and a non-combustible gas filling mechanism, the gas collector having a cavity inside, the gas collection and testing mechanism, the oxygen filling mechanism and the non-combustible gas filling mechanism being connected to the gas collector through orifice flow meters respectively, there are two elbow clamps, which are respectively fixed to the two sides of the upper part of the battery cell fixing mechanism, the battery cell fixing mechanism has a groove in the middle for fixing the battery cell, the lower part of the gas collector has an explosion-proof valve connection hole, the battery cell fixing mechanism fixes the battery cell inside it and then fixes it to the lower part of the gas collector through the elbow clamp, and the explosion-proof valve connection hole contacts and cooperates with the explosion-proof valve on the battery cell.
[0005] Preferably, the oxygen filling mechanism includes a pipeline and an oxygen cylinder connected thereto.
[0006] Preferably, the gas collection and testing mechanism includes a pipeline and an air suction pump connected thereto.
[0007] Preferably, a temperature sensor is provided on the inner wall of the cavity of the gas collector, and the temperature sensor is directly above the explosion-proof valve of the battery cell.
[0008] Preferably, a heating plate is provided on the inner wall of the groove of the battery cell fixing mechanism to heat the battery cell.
[0009] Preferably, a pressure sensor and a temperature cloud sensor are provided on the inner wall of the groove of the battery cell fixing mechanism.
[0010] Preferably, battery cell fixing beams are provided on both sides of the explosion-proof valve connection hole.
[0011] Preferably, the gas collector is provided with two air inlets and one air outlet at its upper portion. The two air inlets are connected to the oxygen injection mechanism and the non-combustible gas injection mechanism, respectively, and the air outlet is connected to the gas collection and testing mechanism. The cell failure gas passes through the gas collector, which is then connected to an orifice plate flowmeter. After the gas passes through the orifice plate flowmeter, the gas flow rate is measured.
[0012] Preferably, a pad is provided above the groove. By adding the pad, different battery cells can be tested.
[0013] Preferably, the orifice flowmeter is used in conjunction with a differential pressure transmitter and a display instrument.
[0014] The beneficial effects of this utility model are that, compared with existing technologies, this device can test the rationality of explosion-proof valve design by detecting the internal pressure of the battery cell. It can also test whether the pack's exhaust capacity, cooling capacity, and sealing capacity after failure meet standards to prevent secondary failure. This device has a simple structure, strong high-temperature gas handling capabilities, and high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a three-dimensional diagram of the utility model;
[0016] Figure 2 It is a three-dimensional diagram of the oxygen filling mechanism in the utility model;
[0017] Figure 3 This is a connection diagram of the orifice plate flowmeter of the utility model;
[0018] Figure 4 This is the principle diagram of the orifice plate flowmeter of the utility model;
[0019] Figure 5 It is a three-dimensional diagram of the gas collector in the utility model in the front and back directions;
[0020] Figure 6 This is a schematic diagram of the installation of the battery cell fixing mechanism and the battery cell in the utility model;
[0021] Figure 7 It is a cross-sectional view of the battery cell fixing mechanism in the utility model;
[0022] Figure 8 It is a three-dimensional diagram of the battery cell fixing mechanism in the utility model;
[0023] Figure 9 yes Figure 8 A partial enlarged view of
[0024] In the figure: 1. Gas collector; 2. Battery cell fixing mechanism; 3. Toggle clamp; 4. Gas collection and testing mechanism; 5. Oxygen filling mechanism; 6. Non-combustible gas filling mechanism; 7. Cavity; 8. Connecting plate; 9. Groove; 10. Explosion-proof valve connection hole; 11. Temperature sensor; 12. Heating plate; 13. Pressure sensor; 14. Temperature cloud sensor; 15. Battery cell fixing beam; 16. Air inlet; 17. Air outlet; 18. Spacer; 19. Orifice flowmeter; 20. Pressure differential transmitter; 21. Explosion-proof valve sealing ring; 22. Gas cylinder; 23. Battery cell to be tested. DETAILED DESCRIPTION
[0025] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.
[0026] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, features defined as "first", "second" and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.
[0027] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fixed connection" and "fixed connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, or it can be internal communication between two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances. The specific implementation methods of the utility model are described in detail below with reference to the accompanying drawings and preferred embodiments.
[0028] like Figure 1-Figure 3 As shown, a device for measuring the critical point of explosion of gas ejected from a failed battery cell comprises a gas collector 1, a battery cell fixing mechanism 2, a toggle clamp 3, a gas collection and testing mechanism 4, an oxygen filling mechanism 5 and a non-combustible gas filling mechanism 6. The gas collector has a cavity 7 inside, and the gas collection and testing mechanism, the oxygen filling mechanism and the non-combustible gas filling mechanism are connected to the gas collector through an orifice flowmeter 19, specifically, as shown in FIG. Figure 5 As shown, the upper part of the gas collector 1 has two air inlet holes 16 and one air outlet hole 17. The two air inlet holes are connected to the oxygen filling mechanism and the non-combustible gas filling mechanism through orifice flow meters, and the air outlet holes are connected to the gas collection and testing mechanism through orifice flow meters. Figure 4 As shown, the orifice flowmeter in this device is a typical differential pressure flowmeter. Used in conjunction with a differential pressure transmitter and display instrument, it can measure fluid flow with a temperature range of up to 850°C and a pressure resistance of up to 32 MPa. The principle is that the fluid filling the pipe flows through a throttling device within the pipe, causing localized contraction near the throttling device, increasing the flow rate and generating a static pressure difference between the upstream and downstream sides. Based on the principle of flow continuity and Bernoulli's equation, the flow rate can be calculated from the pressure difference.
[0029] In this device, the oxygen filling mechanism includes a gas cylinder 22 and a pipeline connected thereto, and the gas collection and testing mechanism includes an air suction pump and a pipeline connected thereto. Both pipelines are connected to the gas collector through an orifice flowmeter.
[0030] like Figure 6-Figure 8 As shown, in this embodiment, there are two toggle clamps, which are respectively fixed to the upper two sides of the battery cell fixing mechanism. The battery cell fixing mechanism has a groove 9 in the middle for fixing the battery cell. The lower part of the gas collector has an explosion-proof valve connection hole 10. The battery cell fixing mechanism fixes the battery cell inside it and then fixes it to the lower part of the gas collector through the toggle clamp. The explosion-proof valve connection hole contacts and cooperates with the explosion-proof valve on the battery cell.
[0031] like Figure 9As shown, a heating plate 12 is provided on the inner wall of the groove of the battery cell fixing mechanism, which has a heating function. In order to monitor the temperature and pressure of the battery cell, a pressure sensor 13 and a temperature cloud sensor 14 are provided on the inner wall of the groove of the battery cell fixing mechanism. The pressure sensor 13 is used to monitor the pressure of the battery cell, and the temperature cloud sensor 14 can monitor the temperature of the battery cell.
[0032] During use, first place the pressure sensor 13 and temperature cloud sensor 14 into the cell fixture, then place the cell to be tested 23 into the fixture. The toggle clamp is mounted on the fixture, which has an internal heating plate, providing a heating function. Furthermore, by adding a spacer 18, different cells can be tested. The explosion-proof valve sealing ring 21 is placed on the explosion-proof valve of the cell to be tested, and then the gas collector is placed on top of the cell fixture. The fixture is positioned using the cell-fixing crossbeam 15 on the fixture. At this point, the explosion-proof valve connection hole and the explosion-proof valve of the cell to be tested are sealed by the sealing ring.
[0033] The device is used in the following ways:
[0034] The heating device of the cell retaining mechanism causes the cell to experience thermal runaway. Rapid gas production within the cell forces the explosion-proof valve to open. At this point, a pressure cloud sensor can be used to monitor the cell pressure. Because the space within the cell retaining mechanism is the same size as the cell, the cell casing cannot deform. Without deformation, the casing cannot exert stress, so the pressure displayed on the cloud equals the internal pressure of the cell.
[0035] The internal space volume of the gas collector is designed and manufactured based on the actual remaining space of the battery cell in the PACK, which can fully test the actual state of the battery cell after failure. In order to test the pressure relief capacity of the explosion-proof valve, it is necessary to test the curve of the internal pressure change over time after the battery cell fails. As long as the internal pressure does not reach the pressure that causes the battery cell shell to rupture, and the temperature of the battery cell does not reach the melting temperature, then the requirements are met. And the faster the pressure relief speed, the better, and the faster the temperature drops, the better. There is a temperature sensor 11 above the explosion-proof valve of the battery cell fixing mechanism, which can detect the maximum temperature of the gas. The temperature cloud map sensor inside the battery cell fixing mechanism can detect the maximum temperature of the battery cell surface to prevent the battery cell from melting. The gas collection test device can recycle the exhaust gas, and the composition analysis can be performed after recovery.
[0036] Another function of this device is to study the critical point at which deflagration occurs when the gas ejected from a failed battery cell premixes with air under high temperature and high pressure. This provides guidance for PACK design regarding exhaust velocity requirements when cell runaway is detected. The device utilizes oxygen injection equipment and a non-combustible gas injection mechanism to premix the combustion-supporting gas in the waste collection device. A flow meter adjusts the air intake to bring the combustion-supporting agent to the test setpoint. At this point, the heating plate in the heating device of the battery cell fixture triggers thermal runaway of the battery cell. The temperature of the ejected gas reaches the flash point or even the ignition point, but the concentration of the combustion-supporting agent is insufficient to support combustion, deflagration, or even explosion of the combustible gas. Once the critical point is detected, the pressure relief valve in the waste collection device's simulated PACK can even be opened simultaneously to reduce the concentration of the combustible gas and test whether deflagration or explosion will occur in the gas collector.
[0037] This new device can also be used to add a cooling device to lower the temperature of the combustion gas, thereby reducing the probability of secondary failure.
[0038] In terms of adding gas, another filling device can add some non-combustible gas to increase the internal pressure and increase the discharge of premixed gas of combustible gas and air.
[0039] It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be regarded as within the scope of protection of the present invention.
Claims
1. A device for measuring the critical point of explosion of gas ejected from a failed battery cell, characterized by: It includes a gas collector, a battery cell fixing mechanism, an elbow clamp, a gas collection and testing mechanism, an oxygen filling mechanism and a non-combustible gas filling mechanism. The gas collector has a cavity inside. The gas collection and testing mechanism, the oxygen filling mechanism and the non-combustible gas filling mechanism are connected to the gas collector through orifice flow meters respectively. There are two elbow clamps, which are respectively fixed to the two sides of the upper part of the battery cell fixing mechanism. The battery cell fixing mechanism has a groove in the middle for fixing the battery cell. The lower part of the gas collector has an explosion-proof valve connection hole. The battery cell fixing mechanism fixes the battery cell inside it and then fixes it to the lower part of the gas collector through the elbow clamp. The explosion-proof valve connection hole contacts and cooperates with the explosion-proof valve on the battery cell.
2. The device for measuring the critical point of explosion of gas ejected from a failed battery cell according to claim 1, characterized in that: The oxygen filling mechanism comprises a pipeline and an oxygen cylinder connected thereto.
3. The device for measuring the critical point of explosion of gas ejected from a failed battery cell according to claim 1, characterized in that: The gas collection and testing mechanism includes a pipeline and an air suction pump connected thereto.
4. The device for measuring the critical point of explosion of gas ejected from a failed battery cell according to claim 1, characterized in that: A temperature sensor is provided on the inner wall of the cavity of the gas collector, and the temperature sensor is directly above the explosion-proof valve of the battery cell.
5. The device for measuring the critical point of explosion of gas ejected from a failed battery cell according to claim 1, characterized in that: A heating plate is provided on the inner wall of the groove of the battery core fixing mechanism.
6. The device for measuring the critical point of explosion of gas ejected from a failed battery cell according to claim 1, characterized in that: A pressure sensor and a temperature cloud map sensor are provided on the inner wall of the groove of the battery core fixing mechanism.
7. The device for measuring the critical point of explosion of gas ejected from a failed battery cell according to claim 1, characterized in that: Battery core fixing beams are provided on both sides of the explosion-proof valve connection hole.
8. The device for measuring the critical point of explosion of gas ejected from a failed battery cell according to claim 1, characterized in that: The upper portion of the gas collector is provided with two air inlets and one air outlet. The two air inlets are respectively connected to the oxygen filling mechanism and the non-combustible gas filling mechanism, and the air outlet is connected to the gas collection and testing mechanism.
9. The device for measuring the critical point of explosion of gas ejected from a failed battery cell according to claim 6, characterized in that: A cushion block is provided above the groove.
10. The device for measuring the critical point of explosion of gas ejected from a failed battery cell according to claim 1, characterized in that: The orifice flowmeter is used in conjunction with a differential pressure transmitter and a display instrument.