Battery explosion prevention processing method, device and system

Abstract

The application discloses a battery explosion prevention processing method, device and system, and relates to the technical field of battery safety. A specific embodiment comprises the following steps: in response to thermal runaway of a single cell in a battery module, obtaining sensor data of the single cell and a non-thermal spread critical residual energy calibrated for the battery module; determining the total releasable energy of the single cell; calculating the valve opening area of an explosion-proof valve possessed by the single cell according to the total releasable energy, the non-thermal spread critical residual energy and the sensor data; and controlling the explosion-proof valve to open based on the valve opening area. Thus, the battery explosion prevention processing can be accurately performed, the probability of thermal spread when a single cell in the battery module experiences thermal runaway can be effectively reduced, and the accurate control of non-spread to other cells when a single cell in the battery module experiences thermal runaway can be realized, thereby ensuring the safety of battery use.

Description

Technical Field

[0001] This application relates to the field of battery safety technology, and in particular to a battery explosion-proof treatment method, device and system. Background Technology

[0002] Currently, in battery systems, explosion-proof measures for batteries typically rely on traditional experience, or involve opening a fixed-area explosion-proof valve to release gas when the internal pressure of the battery module's cells exceeds the critical explosion pressure. This approach to battery explosion-proof measures is not precise enough, leading to a high probability of thermal propagation when a single cell in the battery module experiences thermal runaway, resulting in low battery safety. Summary of the Invention

[0003] In view of this, embodiments of this application provide a battery explosion-proof treatment method, apparatus, and system. In response to thermal runaway in a single cell within a battery module, sensor data for the single cell and the critical remaining energy for no thermal propagation calibrated for the battery module are acquired. The total releaseable energy of the single cell is determined, and the opening area of ​​the explosion-proof valve for the single cell is calculated based on the total releaseable energy, the critical remaining energy for no thermal propagation, and the sensor data. Controlling the opening of the explosion-proof valve based on the opening area can solve the problem that existing battery explosion-proof treatments are not precise enough, and that the probability of thermal propagation is high when a single cell in the battery module experiences thermal runaway, resulting in low battery safety.

[0004] To achieve the above objectives, according to one aspect of the embodiments of this application, a battery explosion-proof treatment method is provided, comprising: In response to thermal runaway in a single cell of the battery module, sensor data for the single cell and the critical remaining energy for no thermal propagation calibrated for the battery module are acquired. Determine the total releaseable energy of a single battery cell, and calculate the opening area of ​​the explosion-proof valve of the single battery cell based on the total releaseable energy, the critical remaining energy without thermal propagation, and sensor data. The opening of the explosion-proof valve is controlled based on the valve opening area.

[0005] Optionally, the critical residual energy without thermal propagation is calibrated as follows: The thermal runaway of a single cell in the sample battery module is triggered at the most critical location. The initial energy of the single cell is gradually reduced, and the surface temperature peak of the single cell adjacent to the sample cell is monitored in real time. The most critical location is the location where the probability of thermal runaway of a single cell is greater than a preset probability threshold. The sample battery module corresponds to the battery module. In response to the surface temperature peak being less than or equal to the electrolyte flash point, the initial energy of the current sample cell is recorded as the sample cell's critical residual energy without thermal propagation. The sample single cell at the most stringent position is summarized to obtain a set of sample critical residual energies without thermal propagation. The smallest sample critical residual energy without thermal propagation is selected from a set of samples as the base energy. Calculate the energy difference between the base energy and the preset safety margin, and determine the energy difference as the critical remaining energy without thermal propagation calibrated for the battery module.

[0006] Optionally, determining the total releaseable energy of a single cell includes: Determine the cell capacity of a single battery cell and the voltage applied to the single battery cell; Based on the cell capacity, voltage, and chemical energy conversion coefficient, the total releaseable energy of a single cell is calculated; and The sensor data includes: the heat release rate curve of a single cell, the pressure change curve inside the sealed cavity where the single cell is located, the pressure difference between the inside and outside of the single cell, the calorific value of the gas ejected when the single cell experiences thermal runaway, and the mass of the substance ejected when the single cell experiences thermal runaway. Based on the total releaseable energy, the critical remaining energy without thermal propagation, and sensor data, the opening area of ​​the explosion-proof valve in a single battery cell is calculated, including: Based on the heat release rate curve and the cavity pressure change curve, the blockage model is calibrated. Based on the calibrated blockage model, simulation calculations are performed on the gas flow rate and gas density to obtain the gas flow rate and gas density of the gas ejected during thermal runaway of a single cell within the blockage structure corresponding to the blockage model. Based on material mass and combined with a pressure difference fitting model, the solid-liquid ejection efficiency of a single battery cell in the event of thermal runaway is calculated. Obtain the flammability value of the combustible material in a single battery cell. Based on the total releaseable energy, critical residual energy without heat spread, gas density, gas flow rate, solid-liquid ejection efficiency, gas calorific value, flammability value, internal and external pressure difference of the single battery cell, and critical conditions, calculate the opening area of ​​the explosion-proof valve in the single battery cell.

[0007] Optionally, based on the total releaseable energy, critical residual energy without thermal propagation, gas density, gas flow rate, solid-liquid ejection efficiency, gas calorific value, material flammability, internal and external pressure difference of a single battery cell, and preset conditions, the opening area of ​​the explosion-proof valve of a single battery cell is calculated, including: Calculate the energy difference between the total releaseable energy and the critical residual energy without thermal propagation; The gas ejection energy is obtained based on the gas density, gas velocity, gas calorific value, and nozzle area. The solid-liquid ejection energy is obtained based on the solid-liquid ejection efficiency, the internal and external pressure difference of a single cell, the time of any event, the material combustion value, and the nozzle area. Based on the energy difference, gas ejection energy, and solid-liquid ejection energy, the nozzle area that meets the preset conditions is calculated, and the calculated nozzle area that meets the preset conditions is determined as the minimum opening area of ​​the explosion-proof valve of a single battery cell.

[0008] Optionally, based on the energy difference, gas ejection energy, and solid-liquid ejection energy, the nozzle area that satisfies the preset conditions is calculated, including: Based on the energy difference, gas ejection energy, solid-liquid ejection energy, and preset conditions, the critical conditions corresponding to the nozzle area are obtained. Calculate the nozzle area that satisfies the critical condition.

[0009] Optionally, the preset conditions are:

[0010] in: vent This refers to the energy of the material ejected during thermal runaway of a single battery cell, including the energy of ejected gases.

[0011] This also includes solid-liquid ejection energy: The total energy that can be released from a single battery cell. Where η is the chemical energy conversion coefficient, C is the cell capacity of a single cell, and V is the voltage applied to a single cell; For the critical remaining energy with no thermal propagation calibrated for the battery module; and The critical condition is:

[0012] In the preset and critical conditions, S is the nozzle area; The gas density within the choking structure corresponding to the choking model is the gas ejected during thermal runaway of a single battery cell. The gas flow velocity within the choking structure corresponding to the choking model is the gas ejected during thermal runaway of a single battery cell. t represents the calorific value of the gas ejected during thermal runaway of a single battery cell; t represents any given moment. The solid-liquid ejection efficiency is represented by ΔP, where ΔP is the internal and external pressure difference of a single cell; H is the external pressure difference of a single cell. mat This refers to the flammability value of the combustible materials within a single battery cell.

[0013] Optionally, the explosion-proof valve is mounted on the base plate of the cover plate of the single cell.

[0014] In addition, this application also provides a battery explosion-proof treatment device, comprising: The thermal runaway response unit is configured to acquire sensor data for the single cell and the critical remaining energy for no thermal propagation calibrated for the battery module in response to thermal runaway of a single cell in the battery module. The valve opening area calculation unit is configured to determine the total releasable energy of a single cell and calculate the valve opening area of ​​the explosion-proof valve of the single cell based on the total releasable energy, the critical residual energy without thermal propagation, and sensor data. The valve opening control unit is configured to control the opening of the explosion-proof valve based on the valve opening area.

[0015] Optionally, the critical residual energy without thermal propagation is calibrated as follows: The thermal runaway of a single cell in the sample battery module is triggered at the most critical location. The initial energy of the single cell is gradually reduced, and the surface temperature peak of the single cell adjacent to the sample cell is monitored in real time. The most critical location is the location where the probability of thermal runaway of a single cell is greater than a preset probability threshold. The sample battery module corresponds to the battery module. In response to the surface temperature peak being less than or equal to the electrolyte flash point, the initial energy of the current sample cell is recorded as the sample cell's critical residual energy without thermal propagation. The sample single cell at the most stringent position is summarized to obtain a set of sample critical residual energies without thermal propagation. The smallest sample critical residual energy without thermal propagation is selected from a set of samples as the base energy. Calculate the energy difference between the base energy and the preset safety margin, and determine the energy difference as the critical remaining energy without thermal propagation calibrated for the battery module.

[0016] Optionally, the valve opening area calculation unit is further configured to: Determine the cell capacity of a single battery cell and the voltage applied to the single battery cell; Based on the cell capacity, voltage, and chemical energy conversion coefficient, the total releaseable energy of a single cell is calculated; and The sensor data includes: the heat release rate curve of a single cell, the pressure change curve inside the sealed cavity where the single cell is located, the pressure difference between the inside and outside of the single cell, the calorific value of the gas ejected when the single cell experiences thermal runaway, and the mass of the substance ejected when the single cell experiences thermal runaway. The valve opening area calculation unit is further configured as follows: Based on the heat release rate curve and the cavity pressure change curve, the blockage model is calibrated. Based on the calibrated blockage model, simulation calculations are performed on the gas flow rate and gas density to obtain the gas flow rate and gas density of the gas ejected during thermal runaway of a single cell within the blockage structure corresponding to the blockage model. Based on material mass and combined with a pressure difference fitting model, the solid-liquid ejection efficiency of a single battery cell in the event of thermal runaway is calculated. Obtain the flammability value of the combustible material in a single battery cell. Based on the total releaseable energy, critical residual energy without heat spread, gas density, gas flow rate, solid-liquid ejection efficiency, gas calorific value, flammability value, internal and external pressure difference of the single battery cell, and critical conditions, calculate the opening area of ​​the explosion-proof valve in the single battery cell.

[0017] Optionally, the valve opening area calculation unit is further configured to: Calculate the energy difference between the total releaseable energy and the critical residual energy without thermal propagation; The gas ejection energy is obtained based on the gas density, gas velocity, gas calorific value, and nozzle area. The solid-liquid ejection energy is obtained based on the solid-liquid ejection efficiency, the internal and external pressure difference of a single cell, the time of any event, the material combustion value, and the nozzle area. Based on the energy difference, gas ejection energy, and solid-liquid ejection energy, the nozzle area that meets the preset conditions is calculated, and the calculated nozzle area that meets the preset conditions is determined as the minimum opening area of ​​the explosion-proof valve of a single battery cell.

[0018] Optionally, the valve opening area calculation unit is further configured to: Based on the energy difference, gas ejection energy, solid-liquid ejection energy, and preset conditions, the critical conditions corresponding to the nozzle area are obtained. Calculate the nozzle area that satisfies the critical condition.

[0019] Optionally, the preset conditions are:

[0020] in: vent This refers to the energy of the material ejected during thermal runaway of a single battery cell, including the energy of ejected gases.

[0021] This also includes solid-liquid ejection energy: The total energy that can be released from a single battery cell. Where η is the chemical energy conversion coefficient, C is the cell capacity of a single cell, and V is the voltage applied to a single cell; For the critical remaining energy with no thermal propagation calibrated for the battery module; and The critical condition is:

[0022] In the preset and critical conditions, S is the nozzle area; The gas density within the choking structure corresponding to the choking model is the gas ejected during thermal runaway of a single battery cell. The gas flow velocity within the choking structure corresponding to the choking model is the gas ejected during thermal runaway of a single battery cell. t represents the calorific value of the gas ejected during thermal runaway of a single battery cell; t represents any given moment. The solid-liquid ejection efficiency is represented by ΔP, where ΔP is the internal and external pressure difference of a single cell; H is the external pressure difference of a single cell. mat This refers to the flammability value of the combustible materials within a single battery cell.

[0023] Optionally, the explosion-proof valve is mounted on the base plate of the cover plate of the single cell.

[0024] In addition, this application provides a battery explosion-proof treatment system, including: Battery module, multiple sensors, and the battery explosion-proof treatment device mentioned above; The battery module includes multiple individual cells, and explosion-proof valves are installed on the substrate of the cover plate of the multiple individual cells. Multiple sensors are installed inside the battery module to acquire sensor data for the single cell that has experienced thermal runaway when thermal runaway occurs in the battery module. The battery explosion-proof treatment device communicates with the battery module and multiple sensors. In response to thermal runaway of a single cell in the battery module, it acquires sensor data for the single cell and the critical remaining energy for no thermal propagation calibrated for the battery module; determines the total releaseable energy of the single cell; and calculates the opening area of ​​the explosion-proof valve of the single cell based on the total releaseable energy, the critical remaining energy for no thermal propagation, and the sensor data; and controls the opening of the explosion-proof valve based on the opening area.

[0025] Optionally, the explosion-proof valve is installed at the center of the surface of the substrate.

[0026] In addition, this application also provides a battery explosion-proof processing electronic device, including: one or more processors; and a storage device for storing one or more programs, which, when executed by one or more processors, cause the one or more processors to implement the battery explosion-proof processing method described above.

[0027] In addition, this application also provides a computer-readable medium storing a computer program for implementing battery explosion-proof processing, which, when executed by an on-board processor, implements the above-described battery explosion-proof processing method.

[0028] To achieve the above objectives, according to another aspect of the embodiments of this application, a computer program product is provided.

[0029] A computer program product according to an embodiment of this application includes a computer program that, when executed by a processor, implements the battery explosion-proof processing method provided in an embodiment of this application.

[0030] One embodiment of the above invention has the following advantages or beneficial effects: In response to thermal runaway in a single cell of a battery module, this application acquires sensor data for the single cell and the critical remaining energy for no thermal propagation calibrated for the battery module; determines the total releaseable energy of the single cell; and calculates the opening area of ​​the explosion-proof valve for the single cell based on the total releaseable energy, the critical remaining energy for no thermal propagation, and the sensor data; and controls the opening of the explosion-proof valve based on the opening area. This achieves precise battery explosion-proof treatment, effectively reducing the probability of thermal propagation when a single cell in the battery module experiences thermal runaway, and thus enabling precise control to prevent thermal runaway from spreading to other cells, ensuring battery safety.

[0031] The further effects of the aforementioned unconventional alternative methods will be explained below in conjunction with specific implementation methods. Attached Figure Description

[0032] The accompanying drawings are provided to better understand this application and do not constitute an undue limitation thereof. Wherein: Figure 1 This is a schematic diagram of the main process of a battery explosion-proof treatment method provided according to an embodiment of this application; Figure 2 This is a schematic diagram of the main process of a battery explosion-proof treatment method provided according to an embodiment of this application; Figure 3 This is a schematic diagram of the main process of a battery explosion-proof treatment method provided according to an embodiment of this application; Figure 4 This is a schematic diagram of the main units of the battery explosion-proof treatment device according to an embodiment of this application; Figure 5a This is a schematic diagram of the composition of a battery explosion-proof treatment system according to an embodiment of this application; Figure 5b This is a schematic diagram of the structure of a single cell in the battery module of the battery explosion-proof treatment system according to an embodiment of this application; Figure 6This is a schematic diagram of the relevant structures involved in the calibration of the critical remaining energy without thermal propagation in a sample battery module according to an embodiment of this application. Figure 7 This is a schematic diagram of the structure of a vehicle according to an embodiment of this application; Figure 8 This is a schematic diagram of the structure of a computer system suitable for implementing the embodiments of this application. Detailed Implementation

[0033] The following description, in conjunction with the accompanying drawings, illustrates exemplary embodiments of this application, including various details to aid understanding. These should be considered merely exemplary. Therefore, those skilled in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this application. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description. The acquisition, storage, use, and processing of data in the technical solutions of this application all comply with relevant national laws and regulations.

[0034] It should be noted that, unless otherwise specified, the embodiments of this application and the technical features thereof can be combined with each other.

[0035] Furthermore, the terms "first," "second," and "third," etc., included in the terminology of this application's embodiments are used to distinguish similar objects and are not necessarily used to describe a specific number or order. It should be understood that such terms can be used interchangeably where appropriate; this is merely a way of distinguishing objects with the same attributes in the embodiments of this application.

[0036] Furthermore, the vehicles involved in the embodiments of this application may be internal combustion engine vehicles that use an engine as a power source, hybrid vehicles that use an engine and an electric motor as power sources, electric vehicles that use an electric motor as a power source, etc.

[0037] State of Charge (SOC) is the state of charge, also known as the percentage of remaining charge. It represents the ratio of the current remaining usable capacity of a battery cell to its nominal total capacity when fully charged, and is usually expressed as a percentage (%).

[0038] Figure 1 This is a schematic diagram of the main flow of a battery explosion-proof treatment method according to an embodiment of this application, as shown below. Figure 1 As shown, the battery explosion-proof treatment method mainly includes the following steps S101-S103.

[0039] Step S101: In response to thermal runaway in a single cell of the battery module, acquire sensor data for the single cell and the critical remaining energy for no thermal propagation calibrated for the battery module.

[0040] In this embodiment, the entity executing the battery explosion-proof treatment method (e.g., a server) can monitor in real time whether each individual cell in the battery module has experienced thermal runaway, and respond to the battery module (e.g., Figure 5a , Figure 5b In the 501) single cell (e.g., Figure 5b A thermal runaway occurred in cell 5011, and the results were obtained for the single cell (e.g., ) that experienced the thermal runaway. Figure 5b The sensor data (5011) and the critical remaining energy for no thermal propagation calibrated for this battery module.

[0041] For example, the obtained data for the single cell that experienced thermal runaway (e.g., Figure 5b The sensor data of 5011 includes: the heat release rate curve corresponding to the single cell that experienced thermal runaway (e.g., the curve of the heat release rate (W) of the single cell that experienced thermal runaway changing with time (s) output by the calorimeter, i.e., the dQ / dt curve), the pressure change curve inside the sealed cavity where the single cell is located (e.g., the curve of the pressure inside the sealed cavity where the single cell is located changing with time output by the high-frequency pressure sensor, i.e., the P(t) curve), the internal and external pressure difference ΔP of the single cell, and the calorific value of the gas ejected by the single cell during thermal runaway. And the mass of the substance ejected during thermal runaway of the single cell (the substance may include ejected gas (e.g., electrolyte vapor decomposition gas), liquid (e.g., volatile electrolyte droplets), solid (e.g., active material particles), specifically a gas-liquid-solid mixture).

[0042] In some embodiments, when calibrating the critical residual energy without thermal propagation for a battery module, the following experimental design can be followed: Triggering thermal runaway in a single cell within the battery module gradually reduces its initial state of charge (SOC). ), to monitor whether adjacent battery cells are ignited.

[0043] Judgment criterion: When the peak surface temperature of adjacent cells is ≤150℃ (electrolyte flash point), record the temperature under this condition. As .

[0044] Example, typical values ​​for XX battery: ≈0.1 ≈0.1η .

[0045] In a battery system, when a cell experiences thermal runaway but it does not spread to other cells, the battery system is said to have achieved No-TP ​​(no thermal propagation). This is an important indicator for measuring the safety performance of a battery system.

[0046] In some embodiments, the critical residual energy for no thermal propagation of a battery module can be calibrated in the following manner: in a sample battery module (e.g., ... Figure 6 The most stringent location (as shown in 600) in the sample battery module (it can be understood that there can be multiple most stringent locations in the sample battery module, here we take...) Figure 6 Taking position B in the middle as an example, trigger the sample single cell (e.g.) Figure 6 Thermal runaway (as shown in 602) gradually reduced the sample single cell (e.g.) Figure 6 The initial energy (corresponding to the initial SOC) of the sample single cell (as shown in 602) is monitored in real time and compared with the sample single cell (e.g. Figure 6 (As shown in 602) Adjacent single cells (such as Figure 6 The surface temperature peak of (as shown in 603) is defined as follows: the most severe location is where the probability of single-cell thermal runaway is greater than a preset probability threshold, i.e., the location with a high risk of heat propagation in the battery module. For example, it could be the geometric center of the battery module or the location determined by simulation analysis as the "weakest and most prone to chain reaction". This sample battery module corresponds to the actual battery module that experienced single-cell thermal runaway (i.e., the sample battery module is exactly the same as or has the smallest difference from the actual battery module that experienced single-cell thermal runaway, to ensure that the critical residual energy without heat propagation calibrated by the sample battery module is accurately applicable to the actual battery module that experienced single-cell thermal runaway); in response to the sample single cell (such as... Figure 6 (As shown in 602) Adjacent single cells (such as Figure 6 The surface temperature peak of the sample cell (as shown in 603) is less than or equal to the electrolyte flash point (e.g., 150°C), and the current sample cell (e.g., 603) is recorded. Figure 6 The initial energy (corresponding to the initial SOC) of the sample single cell (as shown in 602) is used as the initial energy of the sample single cell (e.g. Figure 6 The sample thermal propagation-free critical remaining energy (as shown in 602) is used to calculate the sample thermal propagation-free critical remaining energy of a single cell at the most stringent location. This is then used to obtain a set of sample thermal propagation-free critical remaining energies (e.g., sample thermal propagation-free critical remaining energy 1, sample thermal propagation-free critical remaining energy 2, sample thermal propagation-free critical remaining energy 3). From this set of sample thermal propagation-free critical remaining energies (e.g., sample thermal propagation-free critical remaining energy 1, sample thermal propagation-free critical remaining energy 2, sample thermal propagation-free critical remaining energy 3), the smallest sample thermal propagation-free critical remaining energy (e.g., sample thermal propagation-free critical remaining energy 2) is selected as the base energy. The energy difference between the base energy (e.g., sample thermal propagation-free critical remaining energy 2) and a preset safety margin (e.g., sample thermal propagation-free critical remaining energy 2 - preset safety margin) is calculated, and this energy difference is determined as a conservative, universal module-level thermal propagation-free critical remaining energy for battery module calibration. Example =Sample non-thermal propagation critical residual energy 2 - preset safety margin.

[0047] Step S102: Determine the total releaseable energy of a single cell. Based on the total releaseable energy, the critical remaining energy without thermal propagation, and sensor data, calculate the opening area of ​​the explosion-proof valve of the single cell.

[0048] For example, the capacity of a single cell that has experienced thermal runaway can be determined based on the chemical energy conversion coefficient, the cell capacity of the single cell that has experienced thermal runaway, and the voltage applied to that single cell. Figure 5b Total releaseable energy of 5011 According to the total energy that can be released For this battery module (e.g., Figure 5a , Figure 5b The critical remaining energy without thermal propagation as specified in 501) and the acquired single cell (e.g.,) for thermal runaway. Figure 5b The sensor data of 5011 in the middle is used to calculate the single cell (e.g., Figure 5b The 5011 in the middle has an explosion-proof valve (e.g., Figure 5b The valve opening area is shown in Figure 5014.

[0049] Specifically, explosion-proof valves (e.g., Figure 5b As shown in 5014, it is installed in a single cell (e.g., Figure 5b The cover plate (e.g., shown in 5011) Figure 5b The substrate shown in 5012 (e.g., Figure 5b As shown in 5013, this is to ensure battery safety by controlling the opening of the explosion-proof valve.

[0050] Step S103: Control the opening of the explosion-proof valve based on the valve opening area.

[0051] The explosion-proof valve is controlled to open precisely according to the calculated opening area. This precise control of the explosion-proof valve opening effectively reduces the probability of thermal runaway when a single cell in the battery module experiences thermal runaway. Consequently, it can precisely control the thermal runaway of a single cell in the battery module to prevent it from spreading to other cells, thus ensuring battery safety.

[0052] This embodiment responds to thermal runaway in a single cell within a battery module by acquiring sensor data for that single cell and the critical remaining energy for no thermal propagation calibrated for the entire battery module. It then determines the total releaseable energy of the single cell and calculates the opening area of ​​the explosion-proof valve for that cell based on the total releaseable energy, the critical remaining energy for no thermal propagation, and the sensor data. The opening of the explosion-proof valve is then controlled based on this opening area. This achieves precise battery explosion-proof treatment, effectively reducing the probability of thermal propagation when a single cell in the battery module experiences thermal runaway. Furthermore, it allows for precise control to prevent thermal runaway from spreading to other cells, ensuring battery safety.

[0053] Figure 2 This is a schematic diagram of the main process of a battery explosion-proof treatment method according to an embodiment of this application, as shown below. Figure 2 As shown, the battery explosion-proof treatment method mainly includes the following steps S201-S206.

[0054] Step S201: In response to thermal runaway in a single cell of the battery module, acquire sensor data for the single cell and the critical remaining energy for no thermal propagation calibrated for the battery module.

[0055] Step S202: Determine the cell capacity of a single cell and the voltage applied to the single cell.

[0056] In this application, the cell capacity of a single cell can be the actual capacity. For example, a single cell used for 3 years may have had its actual capacity decayed to 80% of its initial nominal capacity. The cell capacity C (e.g., actual capacity) of the single cell that has experienced thermal runaway and the voltage V applied to that single cell are determined.

[0057] Step S203: Calculate the total releaseable energy of a single cell based on the cell capacity, voltage, and chemical energy conversion coefficient.

[0058] For example, the total energy that can be released from a single cell that experiences thermal runaway. Where η is the chemical energy conversion coefficient, C is the cell capacity of the single cell, and V is the voltage applied to the single cell.

[0059] For example, the sensor data includes: the heat release rate curve corresponding to the single cell that experienced thermal runaway, the pressure change curve inside the sealed cavity where the single cell is located, the pressure difference between the inside and outside of the single cell, the calorific value of the gas ejected by the single cell during thermal runaway, and the mass of the substance ejected by the single cell during thermal runaway.

[0060] Step S204: Based on the heat release rate curve and the cavity pressure change curve, the blockage model is calibrated. Based on the calibrated blockage model, simulation calculations are performed on the gas flow rate and gas density to obtain the gas flow rate and gas density of the gas ejected from the single cell during thermal runaway within the blockage structure corresponding to the blockage model.

[0061] For example, data processing and reverse derivation are performed on the heat release rate curve corresponding to the single battery cell that experienced thermal runaway and the pressure change curve inside the sealed cavity where the single battery cell is located. Specifically, the gas generation rate can be estimated based on the heat release rate curve of the single battery cell that experienced thermal runaway, and the gas accumulation rate can be derived based on the pressure change curve inside the sealed cavity where the single battery cell is located. The ejection flow rate can be solved based on the law of conservation of mass. For example, the ejection flow rate = gas generation rate - gas accumulation rate. Then, the instantaneous gas mass flow rate and the estimated flow rate can be calculated. The calculated instantaneous gas mass flow rate and the estimated flow rate are then used to calculate the instantaneous gas mass flow rate and the estimated flow rate. Input the choking model to obtain the simulated pressure change curve output by the choking model. Compare this simulated pressure change curve with the pressure change curve inside the sealed cavity where the single cell is located in real time. If the comparison result shows a mismatch, adjust the key parameters (e.g., gas production coefficient, nozzle temperature, gas composition, etc.) during "data processing and reverse derivation". If the comparison result shows a high degree of agreement, the choking model calibration is complete. Finally, the gas flow velocity of the gas ejected during thermal runaway of the single cell within the choking structure corresponding to the choking model can be obtained through simulation calculations of the calibrated choking model. and gas density .

[0062] Step S205: Based on the mass of the material and combined with the pressure difference fitting model, calculate the solid-liquid ejection efficiency of a single cell in the event of thermal runaway.

[0063] Based on the mass (represented by m0, i.e., the total ejected mass) of the material ejected during thermal runaway of a single battery cell (which may include ejected gas (e.g., electrolyte vapor decomposition gas), liquid (e.g., volatile electrolyte droplets), and solid (e.g., active material particles), specifically a gas-liquid-solid mixture), combined with a pressure difference fitting model, the solid-liquid ejection efficiency of a single battery cell undergoing thermal runaway is calculated. For example, based on the pressure change curve within the sealed cavity where the thermally runaway single battery cell is located, the mass of the ejected gas is calculated using a pressure difference fitting model, and can be represented by m1. Example solid-liquid ejection efficiency... The mass of solid and liquid actually ejected from the single cell during thermal runaway (e.g., m2, in this example, m2 = m0 - m1) can be considered as a percentage of the total mass of material that could be ejected from the single cell before thermal runaway (which can be expressed as m). 总 This can be expressed as a percentage of the total mass of the electrolyte before thermal runaway in a single cell. For example, the formula for calculating solid-liquid ejection efficiency can be expressed as: = m2 / m 总 =(m0- m1) / m 总 .

[0064] Step S206: Obtain the flammability value of the combustible material in the single cell. Based on the total releaseable energy, critical remaining energy without heat spread, gas density, gas flow rate, solid-liquid ejection efficiency, gas calorific value, flammability value, internal and external pressure difference of the single cell, and critical conditions, calculate the opening area of ​​the explosion-proof valve of the single cell.

[0065] For example, obtain the flammability value H of the combustible material in a single battery cell that has experienced thermal runaway. mat Based on the total energy that can be released from a single cell that experiences thermal runaway. The critical remaining energy without thermal propagation for the battery module containing the single cell that experienced thermal runaway. The gas density within the choking structure corresponding to the choking model of a single-cell thermal runaway gas ejection. The gas flow velocity within the choking structure corresponding to the choking model of a single-cell thermal runaway gas. Solid-liquid ejection efficiency during thermal runaway of a single battery cell The calorific value of the gas ejected during thermal runaway of a single battery cell The flammability value (H) of the combustible material within a single battery cell that experiences thermal runaway. mat Calculate the opening area of ​​the explosion-proof valve for a single battery cell based on the internal and external pressure difference ΔP and critical conditions.

[0066] For example, the above , , , , , ΔP, H mat And at any time t, substitute the following critical condition:

[0067] Where S is the nozzle area, the nozzle area S that meets the critical condition is determined as the minimum opening area of ​​the explosion-proof valve of the single cell that has thermal runaway.

[0068] Step S207: Control the opening of the explosion-proof valve based on the valve opening area.

[0069] The actual control area of ​​the explosion-proof valve opening can be greater than or equal to the minimum opening area, thereby achieving precise battery explosion-proof treatment. This can effectively reduce the probability of thermal runaway when a single cell in the battery module experiences thermal runaway, and thus achieve precise control to prevent the thermal runaway from spreading to other cells, ensuring battery safety.

[0070] Figure 3 This is a schematic diagram of the main process of a battery explosion-proof treatment method according to an embodiment of this application, as shown below. Figure 3 As shown, the battery explosion-proof treatment method mainly includes the following steps S301-S310.

[0071] Step S301: In response to thermal runaway in a single cell of the battery module, acquire sensor data for the single cell and the critical remaining energy for no thermal propagation calibrated for the battery module. .

[0072] Step S302: Determine the cell capacity C of a single cell and the voltage V applied to the single cell.

[0073] Step S303: Calculate the total releaseable energy of a single battery cell based on the cell capacity C, voltage V, and chemical energy conversion coefficient η. .

[0074] The sensor data includes: the heat release rate curve for a single battery cell, the pressure change curve inside the sealed cavity where the single battery cell is located, the pressure difference between the inside and outside of the single battery cell, the calorific value of the gas ejected when the single battery cell experiences thermal runaway, and the mass of the substance ejected when the single battery cell experiences thermal runaway.

[0075] Step S304: Based on the heat release rate curve and the cavity pressure change curve, the choking model is calibrated. Based on the calibrated choking model, simulation calculations are performed on the gas flow rate and gas density to obtain the gas flow rate of the gas ejected during thermal runaway of a single cell within the choking structure corresponding to the choking model. and gas density .

[0076] Step S305: Based on the mass of the material (i.e., the mass of the material ejected during thermal runaway of a single battery cell (which may include ejected gas (e.g., electrolyte vapor decomposition gas), liquid (e.g., volatile electrolyte droplets), and solid (e.g., active material particles), specifically a gas-liquid-solid mixture) corresponding to the total ejected mass), and combined with a pressure difference fitting model (which can calculate the mass of the ejected gas), calculate the solid-liquid ejection efficiency of a single battery cell during thermal runaway. Example = (Total ejected mass - ejected gas mass) / Total electrolyte mass of the single cell before thermal runaway.

[0077] Step S306: Obtain the material flammability value H corresponding to the combustible material in a single battery cell. mat .

[0078] Step S307: Calculate the total energy that can be released. and the critical residual energy without thermal propagation energy difference .

[0079] Step S308, based on gas density Gas flow rate calorific value of gas Given the nozzle area S, the gas ejection energy is obtained: .

[0080] Step S309, based on solid-liquid ejection efficiency The internal and external voltage difference ΔP of a single battery cell, the time t at any given moment, and the material calorific value H. mat Given the nozzle area S, the solid-liquid ejection energy is obtained: .

[0081] Step S310, based on the energy difference Energy emitted from gas and solid-liquid ejection energy The calculation meets the preset conditions. The nozzle area S, where, The calculated result satisfies the preset conditions. The nozzle area S is determined as the minimum opening area of ​​the explosion-proof valve of a single battery cell.

[0082] Specifically, based on the energy difference, gas ejection energy, and solid-liquid ejection energy, the nozzle area that meets the preset conditions is calculated, including: Based on energy difference tota - Energy emitted from gas Solid-liquid ejection energy and preset conditions The critical condition corresponding to the nozzle area is obtained: ; Calculate the nozzle area S that satisfies the above critical conditions.

[0083] Specifically, the preset conditions are:

[0084] in: vent This refers to the energy of the material ejected during thermal runaway of a single battery cell, including the energy of ejected gases.

[0085] This also includes solid-liquid ejection energy: The total energy that can be released from a single battery cell. Where η is the chemical energy conversion coefficient, C is the cell capacity of a single cell, and V is the voltage applied to a single cell; For the critical remaining energy with no thermal propagation calibrated for the battery module; and The critical condition is:

[0086] In the preset and critical conditions, S is the nozzle area; The gas density within the choking structure corresponding to the choking model is the gas ejected during thermal runaway of a single battery cell. The gas flow velocity within the choking structure corresponding to the choking model is the gas ejected during thermal runaway of a single battery cell. t represents the calorific value of the gas ejected during thermal runaway of a single battery cell; t represents any given moment. The solid-liquid ejection efficiency is represented by ΔP, where ΔP is the internal and external pressure difference of a single cell; H is the external pressure difference of a single cell. mat This refers to the flammability value of the combustible materials within a single battery cell.

[0087] Step S311: Control the opening of the explosion-proof valve based on the valve opening area.

[0088] The actual control area of ​​the explosion-proof valve opening can be greater than or equal to the minimum opening area, thereby achieving precise battery explosion-proof treatment. This can effectively reduce the probability of thermal runaway when a single cell in the battery module experiences thermal runaway, and thus achieve precise control to prevent the thermal runaway from spreading to other cells, ensuring battery safety.

[0089] The mathematical model involved in this application is as follows: Formula: Total energy that can be released from a single cell experiencing thermal runaway: Physical meaning: The battery cell can release total chemical energy. Parameter description: η is the chemical energy conversion coefficient (experimentally calibrated or according to empirical coefficient), C is the cell capacity of a single battery cell (Ah), and V is the voltage applied to a single battery cell (V). Formula: Ejected energy: Physical meaning: The energy carried by the material ejected from a single battery cell (energy ejected from gas + energy ejected from solid / liquid). Parameter description: The gas density within the choking structure corresponding to the choking model is the gas ejected during thermal runaway of a single battery cell. The gas flow velocity within the choking structure corresponding to the choking model is the gas ejected during thermal runaway of a single battery cell. t represents the calorific value of the gas ejected during thermal runaway of a single battery cell; t represents any given moment. The solid-liquid ejection efficiency is represented by ΔP, where ΔP is the internal and external pressure difference of a single cell; H is the external pressure difference of a single cell. mat This refers to the flammability value of the combustible materials within a single battery cell. Formula: Critical condition: Physical meaning: The formula for the minimum opening area of ​​an explosion-proof valve; parameter description: Calibration was achieved through module thermal propagation experiments.

[0090] Some parameter calibration methods: Parameter: Gas flow rate Engineering data acquisition method: high-frequency pressure sensor and ARC calorimeter, input into the choke model for calculation. The pressure rises extremely rapidly in the early stage of thermal runaway. 90% of the scenarios meet the choke conditions. Typical value example: ~340m / s; Parameter: Internal and external pressure difference ΔP of a single cell; Engineering acquisition method: obtained through a pressure sensor. Parameter: Gas calorific value Engineering method of obtaining data: ARC calorimeter to measure the heat released by gas combustion. Typical values: H2: 120 MJ / Kg; CO: 10 MJ / Kg. Parameter: Solid-liquid ejection efficiency Engineering acquisition method: collect and weigh the ejected material + pressure difference fitting, typical value example: 0.2~0.5 (for designing the structure of explosion-proof valve).

[0091] This application ensures the energy of the ejected material during thermal runaway by precisely controlling the opening area of ​​the explosion-proof valve. vent satisfy: , It is the critical remaining energy at which a single battery cell will not ignite adjacent cells, which is the critical remaining energy for no thermal propagation calibrated for the battery module. This transforms the traditional empirical explosion-proof valve design into a quantitative energy control model, reducing the probability of thermal propagation from the battery cells.

[0092] Figure 4 This is a schematic diagram of the main units of a battery explosion-proof treatment device according to an embodiment of this application. Figure 4 As shown, the battery explosion-proof treatment device 400 includes a thermal runaway response unit 401, a valve opening area calculation unit 402, and a valve opening control unit 403.

[0093] Thermal runaway response unit 401 is configured to acquire sensor data for the single cell and the critical remaining energy for no thermal propagation calibrated for the battery module in response to thermal runaway of a single cell in the battery module.

[0094] The valve opening area calculation unit 402 is configured to determine the total releasable energy of a single cell and calculate the valve opening area of ​​the explosion-proof valve of the single cell based on the total releasable energy, the critical residual energy without thermal propagation, and sensor data.

[0095] The valve opening control unit 403 is configured to control the opening of the explosion-proof valve based on the valve opening area.

[0096] In some embodiments, the critical remaining energy without thermal propagation is calibrated as follows: Thermal runaway of a single cell is triggered at the most critical location in the sample battery module; the initial energy of the single cell is gradually reduced; the surface temperature peak of adjacent cells is monitored in real time, where the most critical location is the location where the probability of thermal runaway of a single cell is greater than a preset probability threshold, and the sample battery module corresponds to the battery module; in response to the surface temperature peak being less than or equal to the electrolyte flash point, the initial energy of the current single cell is recorded as the critical remaining energy without thermal propagation for the single cell; the critical remaining energies without thermal propagation for the single cells at the most critical location are summarized to obtain a set of critical remaining energies without thermal propagation; the smallest critical remaining energy without thermal propagation is selected from the obtained set of critical remaining energies without thermal propagation as the base energy; the energy difference between the base energy and the preset safety margin is calculated, and the energy difference is determined as the critical remaining energy without thermal propagation calibrated for the battery module.

[0097] In some embodiments, the valve opening area calculation unit 402 is further configured to: determine the cell capacity of a single battery cell and the voltage applied to the single battery cell; calculate the total releaseable energy of the single battery cell based on the cell capacity, voltage, and chemical energy conversion coefficient; and the sensor data includes: the heat release rate curve corresponding to the single battery cell, the pressure change curve inside the sealed cavity where the single battery cell is located, the pressure difference between the inside and outside of the single battery cell, the calorific value of the gas ejected during thermal runaway of the single battery cell, and the mass of the substance ejected during thermal runaway of the single battery cell; the valve opening area calculation unit 402 is further configured to: calculate the total releaseable energy of the single battery cell based on the heat release rate curve and the pressure change curve inside the cavity. The blockage model is calibrated, and simulation calculations are performed on the gas flow rate and gas density based on the calibrated blockage model to obtain the gas flow rate and gas density of the gas ejected during thermal runaway of a single battery cell within the blockage structure corresponding to the blockage model. Based on the mass of the material and combined with the pressure difference fitting model, the solid-liquid ejection efficiency of a single battery cell during thermal runaway is calculated. The material combustion value corresponding to the combustible material in the single battery cell is obtained. Based on the total releaseable energy, the critical residual energy without thermal propagation, gas density, gas flow rate, solid-liquid ejection efficiency, gas calorific value, material combustion value, internal and external pressure difference of the single battery cell, and critical conditions, the opening area of ​​the explosion-proof valve of the single battery cell is calculated.

[0098] In some embodiments, the valve opening area calculation unit 402 is further configured to: calculate the energy difference between the total releasable energy and the critical residual energy without heat spread; obtain the gas ejection energy based on the gas density, gas flow rate, gas calorific value, and nozzle area; obtain the solid-liquid ejection energy based on the solid-liquid ejection efficiency, the internal and external pressure difference of a single battery cell, at any given time, the material combustion value, and the nozzle area; calculate the nozzle area that meets preset conditions based on the energy difference, the gas ejection energy, and the solid-liquid ejection energy; and determine the calculated nozzle area that meets the preset conditions as the minimum valve opening area of ​​the explosion-proof valve of a single battery cell.

[0099] In some embodiments, the valve opening area calculation unit 402 is further configured to: obtain the critical conditions corresponding to the nozzle area based on the energy difference, gas ejection energy, solid-liquid ejection energy and preset conditions; and calculate the nozzle area that satisfies the critical conditions.

[0100] In some embodiments, the preset conditions are:

[0101] in: vent This refers to the energy of the material ejected during thermal runaway of a single battery cell, including the energy of ejected gases.

[0102] This also includes solid-liquid ejection energy: The total energy that can be released from a single battery cell. Where η is the chemical energy conversion coefficient, C is the cell capacity of a single cell, and V is the voltage applied to a single cell; For the critical remaining energy with no thermal propagation calibrated for the battery module; and The critical condition is:

[0103] In the preset and critical conditions, S is the nozzle area; The gas density within the choking structure corresponding to the choking model is the gas ejected during thermal runaway of a single battery cell. The gas flow velocity within the choking structure corresponding to the choking model is the gas ejected during thermal runaway of a single battery cell. t represents the calorific value of the gas ejected during thermal runaway of a single battery cell; t represents any given moment. The solid-liquid ejection efficiency is represented by ΔP, where ΔP is the internal and external pressure difference of a single cell; H is the external pressure difference of a single cell. mat This refers to the flammability value of the combustible materials within a single battery cell.

[0104] In some embodiments, the explosion-proof valve is mounted on the substrate of the cover plate of the single-cell battery.

[0105] It should be noted that the battery explosion-proof treatment method and battery explosion-proof treatment device in this application are related in terms of specific implementation content, so the repeated content will not be described again.

[0106] Figure 5a This is a schematic diagram of the composition of a battery explosion-proof treatment system according to an embodiment of this application. Figure 5a As shown, the battery explosion-proof treatment system 500 includes: Battery module 501, multiple sensors 502 and such Figure 4 The battery explosion-proof treatment device 400 shown is shown. Figure 5b This is a schematic diagram of the structure of a single cell in the battery module of the battery explosion-proof treatment system according to an embodiment of this application. For example... Figure 5b As shown, the battery module 501 includes multiple individual cells (indicated by...). Figure 5b Taking the 5011 as an example), in multiple single cells (taking... Figure 5b (Taking 5011 as an example) An explosion-proof valve 5014 is installed on the base plate 5013 of the cover plate 5012; Multiple sensors are installed within the battery module 501 for use in individual cells (in the battery module 501) Figure 5b Taking the 5011 as an example, when thermal runaway occurs, the single cell that experienced thermal runaway (taking...) Figure 5b (Taking the 5011 model as an example) to acquire sensor data; The battery explosion-proof treatment device 400 is communicatively connected to the battery module 501 and multiple sensors 502, responding to individual cells in the battery module 501 (in order to...). Figure 5b Taking the 5011 cell as an example, thermal runaway occurred, and data was obtained for this single cell (using...). Figure 5b Taking 5011 as an example, the sensor data and the critical remaining energy without thermal propagation calibrated for the battery module 501 are used to determine the single cell (taking 5011 as an example). Figure 5b Taking the 5011 as an example, the total releasable energy of the single cell is calculated based on this total releasable energy, the critical remaining energy without thermal propagation, and sensor data. Figure 5b (Taking 5011 as an example) has the opening area of ​​the explosion-proof valve 5014; the opening of the explosion-proof valve 5014 is controlled based on the opening area.

[0107] In some embodiments, such as Figure 5b As shown, the explosion-proof valve 5014 is mounted at the center of the surface of the substrate 5013 (e.g., Figure 5b (The position shown as A in the diagram).

[0108] Figure 6 This is a schematic diagram of the relevant structures involved in calibrating the critical remaining energy without thermal propagation in a sample battery module according to an embodiment of this application. Figure 6 As shown, the calibration of the critical remaining energy without thermal propagation involves a sample battery module 600, in which a heating element 601 is configured to trigger thermal runaway in a single sample cell (e.g., 602). Specifically, at the most critical location in the sample battery module 600 (understandably, there can be multiple most critical locations in the sample battery module; here, we use...), Figure 6 Taking position B as an example, the thermal runaway of a sample cell (e.g., 602) is triggered, and the initial energy of the sample cell (e.g., 602) is gradually reduced. The energy of adjacent cells (e.g., 602) is monitored in real time. Figure 6 The surface temperature peak of 603) in the sample battery module (understandably, there can be multiple most severe locations in the sample battery module, here we take 603) as an example. Figure 6 Taking position B in the sample battery module 600 as an example, this position represents the location where the probability of thermal runaway of a single battery cell is greater than a preset probability threshold. The sample battery module 600 corresponds to the battery module where a single battery cell thermal runaway actually occurred. In response to a single battery cell adjacent to this sample single battery cell (e.g., 602) (e.g., ...), ... Figure 6The surface temperature peak of sample cell 603 is less than or equal to the electrolyte flash point. The initial energy of the current sample cell (e.g., 602) is recorded as the sample critical residual energy without thermal spread for sample cell (e.g., 602). The sample critical residual energy without thermal spread of sample cells at the most severe location (which can be understood as multiple most severe locations in the sample battery module) is summarized to obtain a set of sample critical residual energies without thermal spread. The smallest sample critical residual energy without thermal spread is selected from the obtained set of sample critical residual energies without thermal spread as the base energy. The energy difference between the base energy and the preset safety margin is calculated, and the energy difference is determined as the critical residual energy without thermal spread calibrated for the battery module.

[0109] like Figure 7 As shown, this application embodiment provides a vehicle 700, which may include, as Figure 5a The battery explosion-proof treatment system 500 shown is shown.

[0110] The following is for reference. Figure 8 It shows a schematic diagram of the structure of a computer system 800 suitable for implementing embodiments of the present application. Figure 8 The computer system shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0111] like Figure 8 As shown, the computer system 800 includes a central processing unit (CPU) 801, which can perform various appropriate actions and processes based on programs stored in read-only memory (ROM) 802 or programs loaded from storage section 808 into random access memory (RAM) 803. The RAM 803 also stores various programs and data required for the operation of the system 800. The CPU 801, ROM 802, and RAM 803 are interconnected via a bus 804. An input / output (I / O) interface 805 is also connected to the bus 804.

[0112] The following components are connected to I / O interface 805: an input section 806; an output section 807 including devices such as cathode ray tubes (CRTs), liquid crystal displays (LCDs), and speakers; a storage section 808 including devices such as hard disks; and a communication section 809 including network interface cards such as LAN cards and modems. The communication section 809 performs communication processing via a network such as the Internet. A drive 810 is also connected to I / O interface 805 as needed. A removable medium 811, such as a magnetic disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on drive 810 as needed so that computer programs read from it can be installed into storage section 808 as needed.

[0113] Specifically, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication section 809, and / or installed from removable medium 811. When the computer program is executed by central processing unit (CPU) 801, it performs the functions defined above in the system of this application.

[0114] It should be noted that the computer-readable medium shown in this application can be a computer-readable signal medium or a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this application, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media can also be any computer-readable medium other than computer-readable storage media, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0115] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0116] The modules described in the embodiments of this application can be implemented in software or hardware. The described modules can also be housed in a processor; for example, a processor may be described as including a thermal runaway response unit, a valve opening area calculation unit, and a valve opening control unit. The names of these modules do not necessarily limit the functionality of the module itself.

[0117] In another aspect, this application also provides a computer-readable medium, which may be included in the device described in the above embodiments; or it may exist independently and not assembled into the device. The computer-readable medium carries one or more programs that, when executed by the device, cause the device to, in response to thermal runaway of a single cell in the battery module, acquire sensor data for the single cell and the critical remaining energy for no thermal propagation calibrated for the battery module; determine the total releasable energy of the single cell; calculate the opening area of ​​the explosion-proof valve of the single cell based on the total releasable energy, the critical remaining energy for no thermal propagation, and the sensor data; and control the opening of the explosion-proof valve based on the opening area.

[0118] The computer program product of this application includes a computer program that, when executed by a processor, implements the battery explosion-proof treatment method in the embodiments of this application.

[0119] According to the technical solution of the embodiments of this application, precise battery explosion-proof treatment can be achieved, which can effectively reduce the probability of thermal runaway when a single cell in the battery module experiences thermal runaway. In this way, precise control can be achieved to prevent thermal runaway from spreading to other cells when a single cell in the battery module experiences thermal runaway, thus ensuring battery safety.

[0120] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can occur depending on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for preventing battery explosion, characterized in that, include: In response to thermal runaway in a single cell of the battery module, sensor data for the single cell and the critical remaining energy for no thermal propagation calibrated for the battery module are acquired. Determine the total releaseable energy of the single cell, and calculate the opening area of ​​the explosion-proof valve of the single cell based on the total releaseable energy, the critical remaining energy without thermal propagation, and the sensor data; The opening of the explosion-proof valve is controlled based on the valve opening area.

2. The method according to claim 1, characterized in that, The critical residual energy without thermal propagation is determined as follows: The thermal runaway of a single cell in the sample battery module is triggered at the most critical location, and the initial energy of the single cell is gradually reduced. The surface temperature peak of the single cell adjacent to the single cell is monitored in real time. The most critical location is the location where the probability of thermal runaway of a single cell is greater than a preset probability threshold. The sample battery module corresponds to the battery module. In response to the surface temperature peak being less than or equal to the electrolyte flash point, the initial energy of the current sample cell is recorded as the sample cell's critical remaining energy without thermal spread. By summing up the sample single cell at the most severe position, a set of sample critical residual energies without thermal propagation is obtained. The smallest sample critical residual energy without thermal propagation is selected from the obtained set of sample critical residual energies without thermal propagation as the base energy; Calculate the energy difference between the base energy and the preset safety margin, and determine the energy difference as the critical remaining energy without thermal propagation calibrated for the battery module.

3. The method according to claim 1, characterized in that, Determining the total releaseable energy of the single cell includes: Determine the cell capacity of the single cell and the voltage applied to the single cell; Based on the cell capacity, the voltage, and the chemical energy conversion coefficient, the total releaseable energy of the single cell is calculated; and The sensor data includes: the heat release rate curve corresponding to the single cell, the pressure change curve inside the sealed cavity where the single cell is located, the pressure difference between the inside and outside of the single cell, the calorific value of the gas ejected when the single cell undergoes thermal runaway, and the mass of the substance ejected when the single cell undergoes thermal runaway. The step of calculating the opening area of ​​the explosion-proof valve in a single battery cell based on the total releasable energy, the critical remaining energy without thermal propagation, and the sensor data includes: Based on the heat release rate curve and the cavity pressure change curve, the blockage model is calibrated. Based on the calibrated blockage model, simulation calculations are performed on the gas flow rate and gas density to obtain the gas flow rate and gas density of the gas ejected by the single cell during thermal runaway within the blockage structure corresponding to the blockage model. Based on the mass of the material, and combined with the pressure difference fitting model, the solid-liquid ejection efficiency of the single cell in the event of thermal runaway is calculated. Obtain the flammability value of the combustible material in the single battery cell, and calculate the opening area of ​​the explosion-proof valve of the single battery cell based on the total releaseable energy, the critical residual energy without heat spread, the gas density, the gas flow rate, the solid-liquid ejection efficiency, the gas calorific value, the flammability value of the material, the internal and external pressure difference of the single battery cell, and the critical conditions.

4. The method according to claim 3, characterized in that, The calculation of the opening area of ​​the explosion-proof valve of the single battery cell based on the total releasable energy, the critical residual energy without thermal propagation, the gas density, the gas flow rate, the solid-liquid ejection efficiency, the gas calorific value, the material combustion value, the internal and external pressure difference of the single battery cell, and preset conditions includes: Calculate the energy difference between the total releasable energy and the critical residual energy without thermal propagation; The gas ejection energy is obtained based on the gas density, the gas flow rate, the gas calorific value, and the nozzle area. The solid-liquid ejection energy is obtained based on the solid-liquid ejection efficiency, the internal and external pressure difference of the single cell, at any given time, the combustion value of the material, and the nozzle area. Based on the energy difference, the gas ejection energy, and the solid-liquid ejection energy, the nozzle area that satisfies the preset conditions is calculated, and the calculated nozzle area that satisfies the preset conditions is determined as the minimum opening area of ​​the explosion-proof valve of the single battery cell.

5. The method according to claim 4, characterized in that, The step of calculating the nozzle area that satisfies the preset conditions based on the energy difference, the gas ejection energy, and the solid-liquid ejection energy includes: Based on the energy difference, the gas ejection energy, the solid-liquid ejection energy, and the preset conditions, the critical conditions corresponding to the nozzle area are obtained. Calculate the nozzle area that satisfies the critical condition.

6. The method according to claim 5, characterized in that, The preset conditions are: in: vent The energy of the material ejected when the single battery cell experiences thermal runaway, including the energy of ejected gas: This also includes solid-liquid ejection energy: The total releaseable energy of the single cell. Where η is the chemical energy conversion coefficient, C is the cell capacity of the single cell, and V is the voltage applied to the single cell; The critical remaining energy with no thermal propagation calibrated for the battery module; and The critical condition is: In the preset conditions and the critical conditions, S is the nozzle area; The gas density of the gas ejected during thermal runaway of the single battery cell within the blockage structure corresponding to the blockage model; The gas flow rate of the gas ejected during thermal runaway of the single battery cell within the blockage structure corresponding to the blockage model; The gas calorific value corresponds to the gas ejected during thermal runaway of the single battery cell; t represents any given moment. The solid-liquid ejection efficiency is ΔP; the internal and external pressure difference of the single cell is ΔP; H mat This refers to the flammability value of the combustible material within the single battery cell.

7. The method according to claim 1, characterized in that, The explosion-proof valve is installed on the base plate of the cover plate of the single battery cell.

8. A battery explosion-proof treatment device, characterized in that, include: A thermal runaway response unit is configured to, in response to thermal runaway in a single cell of the battery module, acquire sensor data for the single cell and the critical remaining energy for no thermal propagation calibrated for the battery module. The valve opening area calculation unit is configured to determine the total releasable energy of the single cell, and calculate the valve opening area of ​​the explosion-proof valve of the single cell based on the total releasable energy, the critical remaining energy without thermal propagation, and the sensor data. The valve opening control unit is configured to control the opening of the explosion-proof valve based on the valve opening area.

9. A battery explosion-proof treatment system, characterized in that, include: Battery module, multiple sensors, and battery explosion-proof treatment device as described in claim 8; The battery module includes multiple individual cells, and an explosion-proof valve is installed on the substrate of the cover plate of the multiple individual cells. Multiple sensors are installed within the battery module to acquire sensor data for a single cell that has experienced thermal runaway when such a cell in the battery module experiences thermal runaway. The battery explosion-proof treatment device is communicatively connected to the battery module and multiple sensors. In response to thermal runaway of a single cell in the battery module, it acquires sensor data for the single cell and the critical remaining energy for no thermal propagation calibrated for the battery module; determines the total releasable energy of the single cell; and calculates the opening area of ​​the explosion-proof valve of the single cell based on the total releasable energy, the critical remaining energy for no thermal propagation, and the sensor data; and controls the opening of the explosion-proof valve based on the opening area.

10. The system according to claim 9, characterized in that, The explosion-proof valve is installed at the center of the surface of the substrate.

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