A battery safety residual pressure evaluation method and device, electronic equipment and storage medium

Abstract

The present application relates to the technical field of battery safety, and particularly relates to a battery safety residual pressure evaluation method and device, electronic equipment and a storage medium, wherein the method comprises: obtaining reference data and a state of a battery cell to be evaluated; constructing a first optimization factor by using the difference between the state of the battery cell to be evaluated and the internal impedance of a brand-new battery cell in the reference data; calculating a second optimization factor by using the change acceleration characteristics of a reference temperature curve and the reference gas generation rate at the current time based on the first optimization factor; constructing a final quality source curve based on the first optimization factor and the second optimization factor; and performing safety evaluation on the battery cell to be evaluated by using the final quality source curve to obtain an evaluation result. Through two-step correction of "pre-explosion" and "dynamic instability pulse", the earlier, more intense and intermittent gas generation behavior caused by cell aging is truly mapped into the CFD model, thereby significantly improving the simulation accuracy and avoiding systematic underestimation of the pressure peak value.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery safety, and in particular to a battery safety residual pressure evaluation method, device, equipment and computer readable storage medium. BACKGROUND

[0002] With the rapid popularization of new energy vehicles and large-scale energy storage systems, lithium ion batteries are widely used in battery packs and energy storage cabins due to their high energy density, long cycle life and other advantages. In a highly integrated and sealed battery cabin, once a single cell is triggered to heat runaway due to overcharge, overheating, collision or aging defects, a large amount of high-temperature, high-pressure combustible and toxic gas will be released instantaneously within milliseconds to seconds. To prevent the cabin from exploding and disintegrating, the existing method is to set a pressure relief valve or a weak structure on the cabin wall, which will automatically open when the internal pressure exceeds the set threshold, guiding the gas to a safe area, thereby protecting the cabin structure and personnel safety.

[0003] However, the existing technical method has the following significant defects:

[0004] Ignoring the influence of cell aging: the cells in actual operation often undergo long-term cycle aging, and their internal impedance increases significantly. Higher impedance leads to faster temperature rise, earlier gas production reaction and more intense initial gas production rate during heat runaway, while the existing "fresh cell" baseline curve cannot reflect this "pre-explosion";

[0005] Unable to capture dynamic instability pulse: the internal structure of the aged cell deteriorates, and a sharp gas production pulse is easily generated during heat runaway. The existing smooth baseline curve cannot reproduce this pulse, resulting in systematic underestimation of the pressure peak value;

[0006] Result deviation brings safety hazards: due to the underestimation of the actual pressure rise rate and instantaneous peak value, the pressure relief valve opening threshold, pressure relief channel size and cabin structure strength may be incorrectly set, and thus the pressure relief is not timely or the cabin explodes during actual heat runaway of the aged cell, forming a serious safety risk;

[0007] In summary, how to design a comprehensive correction method that combines cell aging state, dynamic instability pulse and CFD simulation to improve the safety margin of battery cabin pressure relief path design. SUMMARY

[0008] The present application aims to at least partially solve one of the technical problems in the related art.

[0009] To this end, the first purpose of the present application is to propose a battery safety residual pressure evaluation method to solve the problems that the existing technical means systematically underestimates the actual rise rate and instantaneous peak value of the pressure in the battery cabin, affects the accuracy of the simulation results, and constitutes a serious safety hazard.

[0010] A second object of the present application is to provide a device.

[0011] A third object of the present application is to provide an electronic device.

[0012] A fourth object of the present application is to provide a computer-readable storage medium.

[0013] To achieve the above objects, the first aspect of the present application provides a battery safety residual pressure evaluation method, comprising:

[0014] obtaining reference data and a state of a battery cell to be evaluated;

[0015] constructing a first optimization factor by using the difference between the state of the battery cell to be evaluated and the internal impedance of a brand-new battery cell in the reference data;

[0016] calculating a second optimization factor by using the change acceleration characteristics of a reference temperature curve and the reference gas generation rate at the current time based on the first optimization factor;

[0017] constructing a final mass source curve based on the first optimization factor and the second optimization factor;

[0018] performing safety evaluation on the battery cell to be evaluated by using the final mass source curve to obtain an evaluation result.

[0019] Preferably, the step of obtaining reference data and a state of a battery cell to be evaluated comprises:

[0020] selecting a brand-new single battery cell of the same model as the battery cell to be evaluated as a reference battery cell;

[0021] obtaining the internal impedance of the reference battery cell and recording the reference mass source curve and the reference temperature curve when the reference battery cell experiences thermal runaway;

[0022] obtaining the internal impedance of the battery cell to be evaluated.

[0023] Preferably, the step of constructing a first optimization factor by using the difference between the state of the battery cell to be evaluated and the internal impedance of a brand-new battery cell in the reference data comprises:

[0024] calculating the internal impedance difference value by comparing the impedance of the battery cell to be evaluated with the impedance of the brand-new battery cell;

[0025] calculating the first optimization factor by using the internal impedance difference value based on the cumulative process of the reference gas generation rate curve, and the calculation formula is:

[0026]

[0027] wherein, is the simulation time, an actual internal impedance measured before simulation for an aged battery cell to be simulated, an internal impedance of a brand-new battery cell, a normalized cumulative gas production.

[0028] Preferably, the normalized cumulative gas production calculation formula is:

[0029]

[0030] wherein, a reference mass source curve function.

[0031] Preferably, the calculation of the second optimization factor based on the first optimization factor, using the change acceleration characteristic of the reference temperature curve and the reference gas production rate at the current time comprises:

[0032] monitoring the change acceleration characteristic of the reference temperature curve and taking it as a trigger signal to amplify the gas production rate at the current time;

[0033] calculating the first derivative of the reference temperature curve with respect to time to obtain an instantaneous temperature acceleration, normalizing the instantaneous temperature acceleration, and calculating the second optimization factor based on the normalized instantaneous temperature acceleration and the amplified gas production rate, with the calculation formula being:

[0034]

[0035] wherein, a second derivative of the reference temperature curve with respect to time, a norm in the entire time domain , a reference mass source curve function, a peak value of the reference mass source curve .

[0036] Preferably, the construction of the final mass source curve based on the first optimization factor and the second optimization factor comprises:

[0037] using the first optimization factor and the second optimization factor to correct the original reference mass source curve to obtain the final mass source curve, with the calculation formula being:

[0038]

[0039] wherein, a final mass source curve, a first optimization factor, a second optimization factor. ​

[0040] Preferably, performing a safety assessment on the battery cell to be assessed using the final quality source curve to obtain an assessment result includes:

[0041] The final mass source curve is used as input to simulate the battery compartment pressure relief process, and the safe residual pressure of the battery compartment is evaluated based on the simulation results to obtain an assessment of the thermal runaway risk of the aging battery cell.

[0042] To achieve the above objectives, a second embodiment of the present application provides a battery safety residual pressure assessment device, comprising:

[0043] Data acquisition module, which obtains baseline data and the status of the battery cell to be evaluated;

[0044] A first optimization factor calculation module constructs a first optimization factor by using a difference in internal impedance between the state of the battery cell to be evaluated and a new battery cell in the benchmark data;

[0045] A second optimization factor calculation module, based on the first optimization factor, uses the change acceleration characteristics of the reference temperature curve and the current reference gas production rate to calculate a second optimization factor;

[0046] a curve optimization module, constructing a final mass source curve based on the first optimization factor and the second optimization factor;

[0047] The evaluation module uses the final quality source curve to perform a safety evaluation on the battery cell to be evaluated to obtain an evaluation result.

[0048] To achieve the above-mentioned purpose, a third embodiment of the present application provides an electronic device, comprising: a processor, and a memory communicatively connected to the processor;

[0049] The memory stores computer-executable instructions;

[0050] The processor executes the computer-executable instructions stored in the memory to implement any of the above methods.

[0051] To achieve the above-mentioned purpose, the fourth embodiment of the present application proposes a computer-readable storage medium, including computer-executable instructions stored in the computer-readable storage medium, and the computer-executable instructions are used to implement any of the methods described above when executed by a processor.

[0052] The battery safety residual pressure evaluation method provided by the application can solve the problems of the prior art that the simulation of the pressure relief of the battery cabin relies on new battery cell data and ignores the influence of aging, and can improve the simulation accuracy and avoid systematic underestimation of the pressure peak value.

[0053] Additional aspects and advantages of the application will be made apparent by the following description and the appended claims. BRIEF DESCRIPTION OF DRAWINGS

[0054] The above and / or additional aspects and advantages of the application will become apparent and be readily understood by considering the following detailed description, including the accompanying drawings, in which:

[0055] Figure 1 The flowchart of a first specific embodiment of the battery safety residual pressure evaluation method provided by the application;

[0056] Figure 2 The flowchart of a second specific embodiment of the battery safety residual pressure evaluation method provided by the application;

[0057] Figure 3 The structural block diagram of the battery safety residual pressure evaluation device provided by the embodiment of the application. DETAILED DESCRIPTION

[0058] The core of the application is to provide a battery safety residual pressure evaluation method, device, electronic equipment and computer readable storage medium, which can map the earlier, more intense and intermittent gas generation behavior caused by battery cell aging to the CFD model through two-step correction of "pre-explosion" and "dynamic instability pulse", thereby significantly improving the simulation accuracy and avoiding systematic underestimation of the pressure peak value.

[0059] In order to make the person skilled in the art better understand the application scheme, the application will be further described in detail below in combination with the drawings and specific embodiments. Obviously, the described embodiments are only some of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by the person skilled in the art without creative labor belong to the protection scope of the application.

[0060] Referring to Figure 1 , Figure 1 A flowchart of a first embodiment of a battery safety residual pressure evaluation method provided by the present application; the specific operation steps are as follows:

[0061] Step S101: Obtain reference data and a state of a battery cell to be evaluated;

[0062] Step S102: Use the difference between the state of the battery cell to be evaluated and the internal impedance of a brand-new battery cell in the reference data to construct a first optimization factor;

[0063] Step S103: Based on the first optimization factor, use the change acceleration characteristics of the reference temperature curve and the reference gas generation rate at the current time to calculate a second optimization factor;

[0064] Step S104: Based on the first optimization factor and the second optimization factor, construct a final mass source curve;

[0065] Step S105: Use the final mass source curve to perform safety evaluation on the battery cell to be evaluated, and obtain an evaluation result.

[0066] Based on the above embodiment, the step S101 is described in detail in this embodiment:

[0067] In one embodiment, a brand-new single battery cell of the same model as the battery cell to be evaluated is selected as a reference battery cell; the internal impedance of the reference battery cell is obtained, and the reference mass source curve and the reference temperature curve when the reference battery cell occurs thermal runaway are recorded; and the internal impedance of the battery cell to be evaluated is obtained.

[0068] Specifically, a brand-new single battery cell of the same model as in the battery system to be evaluated and in good health is selected as a reference battery cell. Under the standard test conditions of GB / T 31486-2024 "Electric vehicle power storage battery performance requirements and test methods" and IEC 62660 series standards (for automobile driving secondary lithium ion battery cells), the internal impedance of the reference battery cell is measured and recorded, denoted as . Then, the reference battery cell is placed in a sealed test cavity with a known volume, and is induced to occur thermal runaway by an external triggering method (such as heating or needle puncture). During the whole process of thermal runaway, a high-frequency data acquisition device is used to synchronously record the changes of pressure and temperature in the sealed cavity with time, and the reference mass source curve and the reference temperature curve characterizing the gas generation characteristics of the reference battery cell are obtained.

[0069] Based on the above embodiment, the step S102 is described in detail in this embodiment:

[0070] In one embodiment, the impedance of the battery cell to be evaluated and the impedance of a new battery cell are calculated to obtain an internal impedance difference value. Based on the cumulative progress of the baseline gas production rate curve, the first optimization factor is calculated using the internal impedance difference value, and the calculation formula is:

[0071]

[0072] in, is the simulation time, is the actual internal impedance of the aging cell to be simulated measured before simulation. is the internal impedance of a new cell, is the normalized cumulative gas production.

[0073] The calculation formula for normalized cumulative gas production is:

[0074]

[0075] in, is the reference mass source curve function.

[0076] Based on the above embodiment, this embodiment describes step S103 in detail:

[0077] In one embodiment, the acceleration of the reference temperature curve is monitored and used as a trigger signal to amplify the gas production rate at the current moment; the first-order derivative of the reference temperature curve with respect to time is calculated to obtain the instantaneous temperature acceleration, which is normalized. Based on the normalized instantaneous temperature acceleration and the amplified gas production rate, a second optimization factor is calculated, which is calculated as follows:

[0078]

[0079] in, is the second derivative of the reference temperature curve with respect to time, for In the entire time domain within norm, is the reference mass source curve function, Reference mass source curve peak value.

[0080] Based on the above embodiment, this embodiment describes step S104 in detail:

[0081] In one embodiment, the original reference mass source curve is corrected using the first optimization factor and the second optimization factor to obtain a final mass source curve, which is calculated as follows:

[0082]

[0083] wherein, is the final mass source curve, is the first optimization factor, is the second optimization factor.

[0084] Based on the above embodiment, the present embodiment describes step S105 in detail:

[0085] In one embodiment, the final mass source curve is taken as input for the simulation of the battery compartment pressure relief process, and the safety pressure of the battery compartment is evaluated according to the simulation results, to obtain the evaluation of the thermal runaway risk of the aged battery cell.

[0086] The present embodiment provides a battery safety pressure evaluation method, which addresses the defects of existing battery compartment pressure relief simulation relying on new battery cell data and ignoring the influence of aging. The method uses the measured internal impedance as an aging indicator and corrects through two steps of "pre-explosion" and "dynamic instability pulse", which can map the earlier, more intense and intermittent gas production behavior caused by battery cell aging to the CFD model, thereby significantly improving the simulation accuracy and avoiding systematic underestimation of pressure peak value. The method can quantify the risk of battery cells with different aging degrees, is compatible with existing simulation processes, and directly guides the design of pressure relief valve opening parameters, path layout and structure reinforcement, so that the battery compartment pressure relief scheme is upgraded from "new battery cell assumption safety" to "real safety throughout the life cycle", effectively reducing the explosion, fire or toxic leakage risk caused by pressure relief failure, and comprehensively enhancing the intrinsic safety level of new energy systems.

[0087] Based on the above embodiment, the present embodiment describes the model structure of the battery safety pressure evaluation method, as shown in Figure 2 , specifically as follows:

[0088] Obtain reference data and state parameters of the battery to be evaluated;

[0089] Before the implementation of the present application, the basic data required for subsequent calculation need to be obtained through experiments and measurements. Specifically, they include:

[0090] Select a single battery cell of the same type as the battery system to be evaluated, which is new, in good health, and has a good health status. Under standard test conditions, measure and record the internal impedance of the reference battery cell, denoted as . Then, place the reference battery cell in a sealed test chamber with a known volume, and induce thermal runaway of the reference battery cell by external triggering (such as heating or needle piercing). During the entire process of thermal runaway, use a high-frequency data acquisition device to synchronously record the changes of pressure and temperature in the sealed chamber over time, and obtain the reference mass source curve and the reference temperature curve characterizing the gas production characteristics of the reference battery cell by the known data processing method in the prior art.

[0091] Among them, the data processing method known in the prior art is:

[0092] Step 1: Calculate the instantaneous total gas mass based on the ideal gas state equation ;

[0093] Theoretical basis: Using the ideal gas state equation, , is the basic physical law that describes the state of gas.

[0094] Parameter preparation:

[0095] : Curve of absolute pressure in the sealed cavity changing with time, measured in real time by a high-frequency pressure sensor during the experiment (unit: Pa);

[0096] : The curve of the average temperature of the gas in the sealed cavity measured in real time by the thermocouple during the experiment (unit: K). This curve is the reference temperature curve required by this method. .

[0097] : The known and accurate internal volume of the seal chamber (unit: ).

[0098] : Ideal gas constant, the value is 8.314 J / (mol·K).

[0099] : Average molar mass of thermal runaway gas (unit: kg / mol). This value is based on the main components of thermal runaway products of lithium-ion batteries (such as , , , , The weighted average of the weighted average is used to calculate the ratio of the weighted average to the weighted average. According to literature research, this value is usually in the range of 0.020-0.030 kg / mol.

[0100] Calculation process:

[0101] The ideal gas state equation is transformed into:

[0102]

[0103] Thus, we can calculate any time , the total mass of gas generated in the sealed chamber The formula is:

[0104]

[0105] By substituting the experimental recorded and data points into the above equation, a curve describing the total accumulated gas mass over time can be obtained .

[0106] Second step: Calculate the reference mass source curve by numerical differentiation :

[0107] Theoretical basis: Mass flow rate (i.e. mass source term) is the change in mass per unit time, i.e. the first derivative of accumulated mass with respect to time.

[0108]

[0109] Calculation process:

[0110] Perform numerical differentiation on the discrete accumulated mass data sequence obtained in the previous step , and the instantaneous gas production rate, i.e. the reference mass source curve required by the present invention, can be obtained .

[0111] In actual operation, the central difference method or numerical derivative algorithm with smoothing filtering is usually used to reduce the impact of experimental data noise on the derivative result. For example, for time point , its gas production rate can be approximately calculated as:

[0112]

[0113] where,

[0114] : the gas production rate at time (unit: kg / s or g / s).

[0115] , : the accumulated gas mass corresponding to adjacent time points and (unit: kg or g).

[0116] - : the difference value of time interval (unit: s), used for standardizing the change rate.

[0117] At the same time, for the target aged battery cell to be evaluated for thermal runaway risk in subsequent simulation, its current actual internal impedance is measured and recorded by the battery management system (BMS) , denoted as . The above and constitute all the input data required for subsequent optimization calculation of the present invention.

[0118] Based on the aging state of the battery cell, the reference mass source curve is optimized and corrected in two steps;

[0119] a. Correct the gas production front effect caused by static aging, and obtain the first optimization factor;

[0120] Specifically, the problem to be solved in this step is: how to quantify and simulate the phenomenon that the aging battery cell causes the gas production process to be advanced and more intense due to the increase of internal impedance. Physically, after long-term cyclic use, a series of irreversible electrochemical changes occur in the battery cell, and a significant and easy-to-measure macroscopic representation is the increase of internal impedance. According to Joule's law, when internal short circuit occurs in the battery cell, the heat generated per unit time is proportional to the internal impedance. Therefore, an aging battery cell with higher internal impedance will inevitably have a faster temperature rise rate than a brand new battery cell when the same degree of internal short circuit occurs. Faster temperature rise rate will directly accelerate the process of thermal runaway related chemical reactions, causing the starting threshold of the gas production reaction to be reached earlier, and showing a more intense gas production rate in the initial stage than the brand new battery cell.

[0121] The reference mass source curve used in the prior art Originating from a brand new battery cell, its internal impedance is at the lowest level, so the gas production process described by this curve is relatively gentle. If this curve is directly used to simulate the thermal runaway of an aging battery cell, the initial stage gas production intensity will inevitably be underestimated, resulting in a misjudgment of the pressure rise rate.

[0122] To solve this problem, a dynamic correction factor reflecting the degree of aging must be constructed, which is the first optimization factor. This correction factor amplifies the reference mass source curve in the initial stage of simulation, and the amplification should be positively correlated with the degree of aging of the battery cell; with the progress of the thermal runaway reaction, this amplification effect should gradually weaken and eventually disappear, because aging mainly affects the start and initial rate of the reaction, not the total gas production. Based on this logic, a key indicator that can quantify the degree of aging is first needed, and the relative change in the internal impedance of the battery cell is selected as the key indicator.

[0123] The application constructs a preliminary optimization factor The specific mathematical expression is as follows:

[0124]

[0125]

[0126] Wherein, : preliminary optimization factor changing with time, dimensionless, : simulation time, : actual internal impedance of the aging battery cell to be simulated measured before simulation, : internal impedance of a brand-new cell for generating the reference mass source curve as a reference value, is a reference mass source curve function, representing the gas generation rate of a brand-new cell at time , is the total duration of the reference mass source curve, is the normalized cumulative gas generation amount, representing the completion degree of the thermal runaway reaction at time , and its value range is [0, 1] and is dimensionless.

[0127] The core of the present application is to correlate the measurable physical feature internal impedance with the dynamic behavior of thermal runaway gas generation. The part in the expression gives a dimensionless aging severity index. This index uses the physical quantity that best reflects the aging effect, i.e., internal impedance, compares it with the reference value in the brand-new state, and quantitatively describes the aging degree of the cell to be simulated. The higher the value is, the greater the index is.

[0128] In order to make the correction effect dynamically act on different stages of the gas generation process, the , i.e., the normalized cumulative gas generation amount, is introduced. This term maps the absolute physical time t to a process coordinate representing the completion degree of the reaction varying from 0 to 1. Using the process coordinate instead of the absolute time makes the present method more adaptable to cells with different chemical systems and different total gas generation durations.

[0129] On this basis, the core part of the formula skillfully constructs the form of the correction effect changing with the reaction progress. The value range of the hyperbolic tangent function is , and it changes most rapidly near , and rapidly saturates to as increases. The present application uses the inverse function form of it and constructs in the form of . This makes , the process coordinate , approach , the function value also approach , and the entire part approach at the beginning of the reaction, i.e., takes the maximum value , thereby amplifying the initial gas generation rate to the greatest extent; as the reaction proceeds, the process coordinate gradually increases, and the function value rapidly approaches , Some are rapidly approaching , which ultimately makes Smoothly return to The present invention achieves the correction goal of significant amplification in the early stage and automatic convergence in the later stage, and solves the problem that the existing technology fails to reflect the pre-explosion characteristics of gas production in aging batteries.

[0130] b. Correct the gas production pulse effect caused by dynamic instability to obtain the second optimization factor;

[0131] The details are as follows: After the correction, the problem of premature gas production caused by the initial aging state of the battery cell has been solved. However, in the dynamic process of thermal runaway, there is still a deeper technical problem that needs to be solved. The aging of the battery cell is not only reflected in the change of initial physical parameters, but also in the decline of the stability of its internal chemical system and physical structure. Long-term circulation will cause the solid electrolyte interface membrane (SEM) to Thickening and deterioration of the membrane, or microcracks in the positive and negative electrode materials can occur. Under the rapid temperature rise caused by thermal runaway, these unstable structures are more likely to collapse or undergo unintended violent decomposition reactions. This phenomenon manifests macroscopically as one or more sharp, sudden secondary pulses near or after the main gas production peak, rather than a smooth change in gas production rate.

[0132] This thermal feedback instability phenomenon is dynamic and highly nonlinear. The optimization factor constructed in The shape of the pressure drop is a smoothly decaying function determined by the initial state, which cannot capture sudden pulses that occur randomly or at specific moments during the process. If this effect is ignored, the simulation results will not be able to reproduce the operating conditions of instantaneous pressure jumps, resulting in insufficient margin for the pressure relief design to cope with such extreme pulse shocks.

[0133] Therefore, in Based on this correction, an optimization factor is further constructed that can characterize and amplify this dynamic instability effect. Identifying the source of this instability is crucial. A sudden, violent exothermic reaction inevitably leads to an accelerated temperature rise. A rapid increase in the first-order derivative of the temperature curve, or a positive peak in the second-order derivative of the temperature curve, is the physical indicator of this instability. This step simulates an instability pulse by monitoring the acceleration of temperature changes in the benchmark experiment and using it as a trigger signal to perform a brief and intense secondary amplification of the gas production rate at the corresponding moment.

[0134] It should be noted that the aging of the battery cell will exacerbate the reaction intensity in the unstable structure area. Therefore, the problem to be solved by the present application is not to predict a completely new instability event, but to quantify the enhancement effect of the aging state on the reaction intensity in the dynamic instability sensitive area revealed based on the benchmark experiment.

[0135] To achieve the above logic, the method constructs a refinement optimization factor , the refinement optimization factor, i.e. the second optimization factor, has the following specific mathematical expression:

[0136]

[0137]

[0138]

[0139] wherein, is the refinement optimization factor changing with time. is the temperature change curve of a brand new battery cell in the thermal runaway process, is the benchmark temperature curve is the second derivative of time, i.e. the acceleration of temperature change, is the maximum value function, which ensures correction only when the temperature rises rapidly (i.e. when the second derivative is positive), is the temperature acceleration is the norm of in the entire time domain , which represents the overall fluctuation amplitude of the temperature acceleration and is used as a normalized benchmark, is the benchmark mass source curve function, is the peak value of the benchmark mass source curve .

[0140] The method aims to exploit the dynamic instability information in the thermal runaway process by using another set of synchronous data in the benchmark experiment, the temperature curve . By calculating the second derivative of the temperature curve , the focus is shifted from the temperature itself to the acceleration of temperature change. Because the positive temperature acceleration peak directly corresponds to the emergence of a new and intense exothermic source in the system, which is the physical signal of the heat feedback instability event that needs to be captured. This design ensures that the optimization factor is only activated when the temperature rises rapidly, and when the temperature is stable, slows down or decreases, the factor value is , without any correction.

[0141] The method uses (i.e. the norm) to normalize the instantaneous temperature acceleration. This term converts the instantaneous temperature acceleration into a relative instability intensity signal. This signal will only produce a large value when the instantaneous acceleration significantly exceeds its average fluctuation level throughout the entire process. The first-order derivative of the reference temperature curve with respect to time is the instantaneous temperature acceleration.

[0142] However, the temperature instability signal alone is not enough. The premise of gas pulse production is based on the existing chemical reaction. Therefore, it is necessary to introduce the coupling term This term represents the ratio of the current baseline gas production rate to its peak value. Multiplying the instability intensity signal by this coupling term is significant in that the correction effect is most pronounced only when both the temperature rise and significant gas production are simultaneously met. This effectively avoids the generation of unrealistic spurious pulses due to small temperature fluctuations during stages where gas production should be minimal (in the early or late stages of the reaction), thereby enhancing the physical realism of the model.

[0143] Finally, the entire expression is placed in the natural exponential function When the trigger condition is met, It will form a larger The peak value and width of the sharp pulse are determined by the temperature acceleration and the current gas production, thereby superimposing a dynamic instability pulse on the corrected mass source curve, solving the problem that the existing technology cannot simulate such extreme working conditions.

[0144] c. Generate a corrected mass source curve for integrated aging effects;

[0145] The details are as follows: After the above steps, the preliminary optimization factors for correcting the static aging effect are obtained and a refined optimization factor for correcting dynamic instability effects These two correction effects need to be applied to the original reference mass source curve to obtain an optimized correction mass source curve. The curve includes the pre- and enhanced gas production due to aging, and can also reflect the dynamic instability pulse at a specific moment, thus more realistically reflecting the gas production behavior of aging cells during thermal runaway.

[0146] The calculation formula is:

[0147]

[0148] in, This is the final obtained corrected mass source curve used to replace the single reference curve in the prior art.

[0149] Apply the modified mass source curve to evaluate the safety residual pressure.

[0150] By post-processing analysis on the simulation results, the pressure history curves of the key positions in the battery cabin are extracted to determine the safety residual pressure peak after pressure relief. By comparing the more accurate evaluation results with the structural bearing limit of the battery cabin, a more reliable judgment on the effectiveness and safety of the pressure relief design is made than the prior art, and accurate data support is provided for optimizing the pressure relief path, adjusting the opening parameters of the pressure relief valve and strengthening the local structure.

[0151] Reference is made to Figure 3 , Figure 3 A structural block diagram of a battery safety residual pressure evaluation device provided by an embodiment of the present application is provided; a specific device can include:

[0152] A data acquisition module 100 acquires reference data and a state of an electric cell to be evaluated;

[0153] A first optimization factor calculation module 200 uses the internal impedance difference between the state of the electric cell to be evaluated and the brand new electric cell in the reference data to construct a first optimization factor;

[0154] A second optimization factor calculation module 300 uses the change acceleration characteristics of the reference temperature curve and the reference gas generation rate at the current time based on the first optimization factor to calculate a second optimization factor;

[0155] A curve optimization module 400 constructs a final mass source curve based on the first optimization factor and the second optimization factor;

[0156] An evaluation module 500 uses the final mass source curve to perform safety evaluation on the electric cell to be evaluated to obtain an evaluation result.

[0157] The battery safety residual pressure evaluation device of the embodiment is used to implement the battery safety residual pressure evaluation method described above, and thus the specific embodiments of the battery safety residual pressure evaluation device can refer to the embodiment part of the battery safety residual pressure evaluation method described above, for example, the data acquisition module 100, the first optimization factor calculation module 200, the second optimization factor calculation module 300, the curve optimization module 400, and the evaluation module 500 are respectively used to implement steps S101, S102, S103, S104, and S105 in the battery safety residual pressure evaluation method described above, and thus the specific embodiments can refer to the description of the respective embodiment parts, and will not be described here.

[0158] In order to implement the above-mentioned embodiments, the present application further provides an electronic device, which comprises a processor and a memory connected with the processor in communication; the memory stores computer execution instructions; and the processor executes the computer execution instructions stored in the memory to implement the method provided by the above-mentioned embodiments.

[0159] To achieve the above-mentioned embodiments, the present application further provides a computer readable storage medium, wherein the computer readable storage medium stores computer execution instructions, and the computer execution instructions are executed by a processor to implement the method provided by the foregoing embodiments.

[0160] To achieve the above-mentioned embodiments, the present application further provides a computer program product, comprising a computer program, wherein the computer program is executed by a processor to implement the method provided by the foregoing embodiments.

[0161] The collection, storage, use, processing, transmission, provision and disclosure of user personal information involved in the present application comply with relevant laws and regulations and do not violate public order and good customs.

[0162] It should be noted that the personal information from the user should be collected for legal and reasonable purposes, and should not be shared or sold outside these legal uses. In addition, such collection / sharing should be carried out after the user's informed consent is received, including but not limited to informing the user to read the user agreement / user notice before the user uses the function, and signing the agreement / authorization including authorization of relevant user information. In addition, any necessary steps should be taken to protect and ensure access to such personal information data, and to ensure that other people with access to personal information data comply with their privacy policy and processes.

[0163] The present application is expected to provide embodiments in which the user can selectively prevent the use or access of personal information data. That is, the present disclosure is expected to provide hardware and / or software to prevent or block access to such personal information data. Once the personal information data is no longer needed, the risk is minimized by limiting data collection and deleting data. In addition, such personal information is de-identified, if applicable, to protect the privacy of the user.

[0164] In the foregoing embodiment description, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples, without contradiction.

[0165] Moreover, the terms "first", "second", "third", etc. are used herein only to describe different steps or categories of steps in a claim for patent purposes, and are not to be construed as indicating or implying relative importance of one step to another or a quantity of steps. Thus, features defined with "first", "second" or "third" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "plurality" is at least two, for example, two, three, etc., unless otherwise explicitly and specifically limited.

[0166] Any process or method descriptions or blocks in flow charts herein, and elsewhere, can be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps in the process, and that the various embodiments of the application can include memory or memories for storing some or all of these instructions. These memory or memories can be transitory or non-transitory computer-readable media used to store and transport commands or data structures. Furthermore, whether such instructions are implemented as computer software applications or firmware, translation to software applications or firmware will be understood by those of ordinary skill in the art in light of the disclosure. In addition, various embodiments of the application are well suited to a hardware- and / or software-only implementation. Accordingly, the terms "machine-readable medium" and "computer-readable medium" used herein, unless specifically stated to the contrary, are to be interpreted broadly, including transitory or non-transitory computer-readable media.

[0167] The logic and / or steps represented in flow charts herein, and elsewhere, can be thought of as a list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor- containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this specification, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-readable medium can specifically include an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection (electronic) having one or more wires, a portable computer diskette (magnetic), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber (optical), and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, for example, via an optical scanner, then compiled, interpreted, or otherwise processed, and stored in a computer memory in a form that can be later executed by a computer. In another embodiment, the various embodiments of the application can also be implemented only as software applications, firmware, or digital circuitry. Of course, where a technology is described as being implemented as software, firmware, or digital circuitry, such technology is also contemplates as being implemented by a combination of both hardware and software, even though such a combination is not explicitly described or illustrated herein. In addition, the embodiments of the application described herein can be implemented across many different types of computing systems, including cloud computing systems. Accordingly, the terms "machine-readable medium" and "computer-readable medium," as used herein, include one or both of non-transitory and transitory computer-readable media.

[0168] It should be understood that parts of the present application can be realized in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be realized as software or firmware stored in a memory and executed by a suitable instruction execution system. As such, if realized in hardware, and in another embodiment, any one or a combination of the following technologies known in the art can be used: discrete logic circuitry having logic gates for implementing logic functions on data signals, application specific integrated circuits having appropriate combinational logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), and the like.

[0169] Those skilled in the art of the present technology can understand that all or part of the steps carried out by the above-mentioned embodiments can be completed by a program instructing the relevant hardware, and the program can be stored in a computer readable storage medium. When the program is executed, it includes one of the steps of the method embodiments or a combination thereof.

[0170] In addition, each functional unit in each embodiment of the present application can be integrated in one processing module, or each unit can be physically present separately, or two or more units can be integrated in one module. The above-mentioned integrated module can be realized in the form of hardware or in the form of a software functional module. The integrated module, if realized in the form of a software functional module and sold or used as an independent product, can also be stored in a computer readable storage medium.

[0171] The above-mentioned storage medium can be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-mentioned embodiments within the scope of the present application.

Claims

1. A battery safety residual pressure assessment method, characterized in that: include: Obtain baseline data and the status of the battery cell to be evaluated, including: Select a new single cell of the same model as the cell to be evaluated as the reference cell; Obtaining the internal impedance of the reference battery cell, and recording a reference mass source curve and a reference temperature curve representing a gas production rate of the reference battery cell when thermal runaway occurs in the reference battery cell; Obtain the internal impedance of the battery cell to be evaluated; Using the difference between the state of the battery cell to be evaluated and the internal impedance of a new battery cell in the benchmark data, a first optimization factor is constructed, including: Calculate the impedance of the battery cell to be evaluated and the impedance of a new battery cell to obtain the internal impedance difference value; Based on the cumulative progress of the baseline gas production rate curve, the first optimization factor is calculated using the internal impedance difference value, and the calculation formula is: in, is the simulation time, is the actual internal impedance of the aging cell to be simulated measured before simulation. is the internal impedance of a new cell, is the normalized cumulative gas production; Based on the first optimization factor, the second optimization factor is calculated using the acceleration characteristics of the reference temperature curve and the reference gas production rate at the current moment, including: Monitoring the acceleration characteristics of the reference temperature curve and using it as a trigger signal to amplify the gas production rate at the current moment; The first-order derivative of the reference temperature curve with respect to time is calculated to obtain an instantaneous temperature acceleration, which is normalized. Based on the normalized instantaneous temperature acceleration and the amplified gas production rate, a second optimization factor is calculated. The calculation formula is: in, is the second derivative of the reference temperature curve with respect to time, for In the entire time domain within norm, is the reference mass source curve function, Reference mass source curve Peak value; Based on the first optimization factor and the second optimization factor, the original reference mass source curve is corrected to construct a final mass source curve; The final quality source curve is used to perform a safety assessment on the battery cell to be assessed to obtain an assessment result.

2. The battery safety residual pressure assessment method according to claim 1, characterized in that: The normalized cumulative gas production calculation formula is: in, is the reference mass source curve function, is the total duration of the baseline quality source curve.

3. The battery safety residual pressure assessment method according to claim 1, characterized in that: The constructing a final quality source curve based on the first optimization factor and the second optimization factor includes: The original reference mass source curve is corrected using the first optimization factor and the second optimization factor to obtain a final mass source curve, which is calculated as follows: in, is the final mass source curve, is the first optimization factor, is the second optimization factor.

4. The battery safety residual pressure assessment method according to claim 1, characterized in that: The method of using the final quality source curve to perform a safety assessment on the battery cell to be assessed and obtaining the assessment result includes: The final mass source curve is used as input to simulate the battery compartment pressure relief process, and the safe residual pressure of the battery compartment is evaluated based on the simulation results to obtain an assessment of the thermal runaway risk of the aging battery cell.

5. A battery safety residual pressure assessment device, characterized in that: Used to implement the method according to any one of claims 1 to 4.

6. An electronic device, characterized in that: include: a processor, and a memory communicatively connected to the processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory to implement the method according to any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 4 when executed by a processor.

Images