Battery evaluation method and device based on safety area modeling

Abstract

The invention discloses a battery evaluation method based on safety area modeling, and belongs to the technical field of battery safety. The method comprises the following steps: acquiring running state data of a battery, wherein the running state data comprises current density, battery temperature and battery charge state; the operation state data are input into a force-heat-electricity safety boundary model, the safety radius of the operation state data in the safety space is obtained, and the force-heat-electricity safety boundary model is a three-dimensional model constructed based on the safety space; the safety space is a three-dimensional space formed based on a force safety model boundary, a thermal safety model boundary and a voltage safety model boundary; based on the safety radius, the safety of the battery is evaluated, and the method improves the safety and reliability of the battery.

Description

Technical Field

[0001] The present application belongs to the field of battery safety technology, and in particular, relates to a battery evaluation method based on safety area modeling. Background Art

[0002] Under the guidance of the "dual carbon" goals, batteries have occupied an important position in the field of new energy vehicles and have become a key technology to promote the development of electrified transportation. However, frequent battery safety accidents have posed a serious threat to people's lives and property. Therefore, ensuring the safety of batteries throughout their life cycle has become a major need of the industry.

[0003] The battery safety boundary is the standard for judging whether the battery is in a safe state of use. It is usually defined through battery abuse testing or modeling. Related technologies mainly establish a thermal runaway critical model for lithium batteries by modifying the model, or use an improved single particle model to estimate the safety boundary of the lithium battery charging current.

[0004] At present, there is no unified definition and classification standard for the safety status of batteries. Most of the related technologies define the safety boundaries of batteries based on the data from abuse tests when the batteries leave the factory, that is, directly setting safety thresholds, which results in poor accuracy of safety boundaries. Summary of the invention

[0005] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a battery evaluation method based on safe area modeling to improve the safety and reliability of the battery.

[0006] In a first aspect, the present application provides a battery evaluation method based on safety area modeling, the method comprising: Acquiring operating status data of the battery, wherein the operating status data includes current density, battery temperature, and battery state of charge; The operating status data is input into a force-heat-electricity safety boundary model to obtain a safety radius of the operating status data in a safety space, wherein the force-heat-electricity safety model is a three-dimensional model constructed based on the safety space, and the safety space is a three-dimensional space composed of a force safety model boundary, a thermal safety model boundary, and a voltage safety model boundary; Based on the safety radius, the safety of the battery is evaluated.

[0007] According to one embodiment of the present application, the process of establishing the force safety model includes: Obtaining parameter data of the battery, the parameter data including battery surface area, heat dissipation coefficient, internal free volume of the battery, coolant heat dissipation coefficient, and volume expansion coefficient; Based on the parameter data, obtaining a volume change rate of the battery; Obtaining an expansion pressure of the battery based on a volume change rate of the battery; Constructing constraints of the force safety model based on the expansion pressure of the battery; Based on the constraints of the force security model, the force security model is constructed.

[0008] According to one embodiment of the present application, the process of establishing the thermal safety model includes: Based on the parameter data, a transient energy equation of the battery is obtained; Constructing constraints of the thermal safety model based on the transient energy equation of the battery; Based on the constraints of the thermal safety model, the thermal safety model is constructed.

[0009] According to an embodiment of the present application, the process of establishing the voltage safety model includes: Based on the parameter data, obtaining the voltage of the battery; Constructing constraints of the voltage safety model based on the voltage of the battery; Based on the constraints of the voltage safety model, the voltage safety model is constructed.

[0010] According to one embodiment of the present application, the process of establishing the mechanical-thermal-electrical safety boundary model includes: Constructing a state space of the battery based on the current density, battery temperature, and battery state of charge; Traversing all state points of the state space, and obtaining the force safety model boundary, the thermal safety model boundary, and the voltage safety model boundary based on least squares fitting; Based on the force safety model boundary, the thermal safety model boundary and the voltage safety model boundary, the safety space is obtained by the following formula:

[0011] Where j represents the current density, T represents the battery temperature, and SoC represents the battery state of charge. Represents the force safety model boundary, represents the thermal safety model boundary, represents the voltage safety model boundary, and R represents the safety space.

[0012] According to an embodiment of the present application, the force safety model boundary, the thermal safety model boundary and the voltage safety model boundary may be obtained by the following formula:

[0013] Where j represents the current density, T represents the battery temperature, and SoC represents the battery state of charge. Represents the security model boundary, Represents the coefficients of the fitted function.

[0014] According to an embodiment of the present application, the evaluating the safety of the battery based on the safety radius includes: Determine whether the safety radius is greater than a preset radius threshold; When the safety radius is less than or equal to a preset radius threshold, determining that the safety of the battery is too low, and executing a first operation, the first operation is used to stop the operation of the battery; When the safety radius is greater than a preset radius threshold, the safety of the battery is determined to be normal, and the above-mentioned steps of obtaining the operating status data of the battery are repeated. The operating status data is input into a mechanical-thermal-electrical safety boundary model to obtain a safety radius of the operating status data in a safety space.

[0015] In a second aspect, the present application provides a battery evaluation device based on safe area modeling, the device comprising: An acquisition module, used to acquire the operating status data of the battery, wherein the operating status data includes current density, battery temperature, and battery state of charge; a processing module, configured to input the operating status data into a force-heat-electricity safety boundary model to obtain a safety radius of the operating status data in a safety space, wherein the force-heat-electricity safety model is a three-dimensional model constructed based on the safety space, and the safety space is a three-dimensional space composed of a force safety model boundary, a thermal safety model boundary, and a voltage safety model boundary; An evaluation module is used to evaluate the safety of the battery based on the safety radius.

[0016] In a third aspect, the present application provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the battery evaluation method based on safety area modeling as described in the first aspect above is implemented.

[0017] In a fourth aspect, the present application provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the battery evaluation method based on safe area modeling as described in the first aspect above is implemented.

[0018] In a fifth aspect, the present application provides a chip, comprising a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run a program or instruction to implement the battery evaluation method based on safe area modeling as described in the first aspect.

[0019] In a sixth aspect, the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the battery evaluation method based on safe area modeling as described in the first aspect above.

[0020] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application.

[0021] The battery evaluation method based on safety area modeling provided by the present invention has the following beneficial effects compared with the prior art: The present invention obtains the safety radius of the battery operating state in the safety space by inputting the battery operating state data into the force-thermal-electrical safety boundary model. The model is constructed based on the three-dimensional safety space composed of the force safety model, the thermal safety model and the voltage safety model. It can comprehensively evaluate the safety of the battery. By analyzing the safety radius, it can be determined whether the current working state of the battery is in the safe area, thereby improving the safety and reliability of the battery.

[0022] (2) The present invention can realize the safety prediction of batteries under different operating environments by establishing a mechanical-thermal-electrical safety boundary model. The model boundary is fitted by the least squares method, and the state space of the battery is constructed by combining the current density, battery temperature and state of charge. Based on this, the safety space of the battery is evaluated. By traversing the state space, the safety state of the battery under different working conditions can be judged, thereby improving the stability and safety of the battery operation.

[0023] (3) The present invention is based on the comparison between the safety radius and the preset threshold, and triggers the corresponding operation when the safety radius of the battery is less than or equal to the preset threshold, thereby reducing the possibility of battery failure or accident, improving the safety and stability of the battery during use, and reducing the safety hazards caused by battery failure. Through the evaluation results of the safety radius, battery safety management and response can be carried out in a timely manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 It is one of the flow diagrams of the battery evaluation method based on safety area modeling provided in the embodiment of the present application; Figure 2 is a schematic diagram of a battery safety space provided in an embodiment of the present application; Figure 3 This is the second flow chart of the battery evaluation method based on safety area modeling provided in the embodiment of the present application; Figure 4is a schematic structural diagram of a battery evaluation device based on safe area modeling provided in an embodiment of the present application; Figure 5 It is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0026] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0027] In the following, in combination with the accompanying drawings, the battery evaluation method based on safe area modeling, the battery evaluation device based on safe area modeling, the electronic device and the readable storage medium provided in the embodiments of the present application are described in detail through specific embodiments and their application scenarios.

[0028] Among them, the battery evaluation method based on safe area modeling can be applied to the terminal, and can be specifically executed by hardware or software in the terminal.

[0029] The terminal includes, but is not limited to, a portable communication device such as a mobile phone or a tablet computer having a touch-sensitive surface (e.g., a touch screen display and / or a touch pad). It should also be understood that in some embodiments, the terminal may not be a portable communication device, but a desktop computer having a touch-sensitive surface (e.g., a touch screen display and / or a touch pad).

[0030] In the following various embodiments, a terminal including a display and a touch-sensitive surface is described. However, it should be understood that the terminal may include one or more other physical user interface devices such as a physical keyboard, a mouse and a joystick.

[0031] The battery evaluation method based on safe area modeling provided in the embodiment of the present application may be executed by an electronic device or a functional module or functional entity in the electronic device that can implement the battery evaluation method based on safe area modeling. The electronic devices mentioned in the embodiment of the present application include but are not limited to mobile phones, tablet computers, computers, cameras, and wearable devices. The battery evaluation method based on safe area modeling provided in the embodiment of the present application is described below using an electronic device as an example of the execution subject.

[0032] Figure 1 This is one of the flow charts of the battery evaluation method based on safe area modeling provided in the embodiment of the present application, such as Figure 1 As shown, the battery evaluation method based on safe area modeling includes: step 110, step 120, step 130 and step 140.

[0033] Step 110, obtaining battery operation status data, wherein the battery operation status data includes current density, battery temperature, and battery state of charge; Optionally, the battery can be a lithium battery, a lead-acid battery, a nickel-metal hydride battery, or the like.

[0034] Taking a lithium battery as an example, during the operation of the lithium battery, the operation status data of the lithium battery in the current state is obtained, and the operation status data includes current density, battery temperature and battery charge state.

[0035] It can be understood that current density refers to the amount of current flowing per unit area, which indicates the current size per unit area when the battery is working. Battery temperature refers to the temperature of the battery when it is working. State of charge SOC indicates the percentage of the battery's current remaining power relative to its maximum capacity. SOC generally varies between 0% and 100%.

[0036] Step 120: input the operating status data into a force-heat-electricity safety boundary model to obtain a safety radius of the operating status data in a safety space, wherein the force-heat-electricity safety model is a three-dimensional model constructed based on the safety space, and the safety space is a three-dimensional space composed of a force safety model boundary, a thermal safety model boundary, and a voltage safety model boundary; It should be noted that by obtaining battery parameter data, the battery parameter data includes parameters such as battery surface area, heat dissipation coefficient, battery internal free volume, coolant heat dissipation coefficient, ambient temperature, etc., based on the battery parameter data, the force safety model boundary, thermal safety model boundary and voltage safety model boundary are obtained respectively. The three-dimensional space composed of the force safety model boundary, the thermal safety model boundary and the voltage safety model boundary is the safety space, and the force-heat-electricity safety model is constructed through the safety space.

[0037] Furthermore, the operating status data of the battery is input into the mechanical-thermal-electrical safety model to calculate the safety radius of the current battery, where the safety radius is the shortest distance between the operating status data of the battery and the boundary of the safety space.

[0038] Step 130: Evaluate the safety of the battery based on the safety radius.

[0039] Finally, the mechanical-thermal-electrical safety model outputs the safety radius of the battery to the electronic device, which determines the relationship between the safety radius of the battery and a preset radius threshold. When the safety radius is less than or equal to the preset radius threshold, it is determined that the safety of the battery is too low, and the electronic device controls the battery to stop running. When the safety radius is greater than the preset radius threshold, it is determined that the safety of the battery is normal, and the above steps 110 and 120 are repeated.

[0040] According to the battery assessment method based on safety area modeling provided in the embodiment of the present application, the battery operating status data is input into the force-thermal-electrical safety boundary model to obtain the safety radius of the battery operating status in the safety space. The model is constructed based on the three-dimensional safety space composed of the force safety model, the thermal safety model and the voltage safety model, and can comprehensively evaluate the safety of the battery. By analyzing the safety radius, it is possible to determine whether the current working state of the battery is in the safety area, and by real-time monitoring of changes in parameters such as current density, battery temperature, and battery state of charge, potential risk factors can be quickly identified. By combining a multi-dimensional safety model, the mutual influence of different factors is considered in the evaluation process, thereby improving the accuracy and reliability of battery safety assessment, reducing the risk of system failure or safety accidents, and effectively extending the service life of the battery. It is suitable for the entire life cycle of the battery, and the safety boundary model is simple, small in calculation, and strong in real time.

[0041] In some embodiments, the process of establishing the force safety model includes: Obtaining parameter data of the battery, the parameter data including battery surface area, heat dissipation coefficient, internal free volume of the battery, coolant heat dissipation coefficient, and volume expansion coefficient; Based on the parameter data, obtaining a volume change rate of the battery; Obtaining an expansion pressure of the battery based on a volume change rate of the battery; Constructing constraints of the force safety model based on the expansion pressure of the battery; Based on the constraints of the force security model, the force security model is constructed.

[0042] It is easy to understand that a series of complex electrochemical reactions will occur during the charging and discharging process of the battery. These reactions involve the decomposition of the electrolyte, the insertion and extraction reactions of the electrode materials, and the occurrence of side reactions. These reactions will cause the battery to swell and the internal pressure to increase. The process of establishing a force safety model through the battery expansion pressure is as follows: (1) Obtaining parameter data of the battery, the parameter data including at least one of the battery surface area, heat dissipation coefficient, internal free volume of the battery, coolant heat dissipation coefficient, volume expansion coefficient, etc.; (2) Based on the battery parameter data, the change in battery embedding amount is obtained, and the calculation formula is as follows:

[0043] in, is the change in embedding amount, is the current density, is the electrode active area, is the duration, is the number of moles of electrons in the reaction, is Faraday's constant.

[0044] Based on the changes in the initial volume of the battery and the amount of battery embedded, the volume change rate of the battery embedding reaction is obtained, and the calculation formula is as follows:

[0045] in, is the volume change rate of the battery insertion and extraction reaction, is the initial volume of the battery, is the change in the amount of battery embedded, It is the volume expansion coefficient related to the material properties.

[0046] Based on the volume change rate of the battery and the initial volume of the battery, the battery expansion pressure caused by the insertion and extraction reaction is obtained, and the calculation formula is as follows:

[0047] in, is the battery volume change rate, is the initial volume of the battery, is the Young's modulus of the material, is the battery expansion pressure caused by the insertion and extraction reaction, is the volume expansion coefficient related to the material properties, is the current density, is the electrode active area, is the duration, is the number of moles of electrons in the reaction, is Faraday's constant.

[0048] In addition, the temperature change caused by the current will also cause the battery volume to expand. The volume change rate due to the battery temperature change is calculated as follows:

[0049] in, is the rate of change of battery volume caused by temperature change, is the coefficient of thermal expansion, is the temperature change, is the initial volume of the battery.

[0050] The calculation formula for the battery expansion pressure caused by battery temperature changes is as follows:

[0051] in, is the rate of change of battery volume caused by temperature change, is the coefficient of thermal expansion, is the temperature change, is the battery expansion pressure caused by battery temperature changes, is the Young's modulus of the material, is the initial volume of the battery.

[0052] (3) The total expansion pressure of the battery can be expressed as:

[0053] in, is the battery expansion pressure caused by the insertion / extraction reaction, is the battery expansion pressure caused by battery temperature change, and P is the total expansion field strength of the battery.

[0054] (4) Based on the expansion pressure of the battery, the constraints of the force safety model are constructed. The constraints of the force safety model are as follows:

[0055] Where P is the total expansion field strength of the battery, It is the upper limit of battery expansion pressure.

[0056] (5) Construct a force safety model based on the constraints of the force safety model.

[0057] In this embodiment, the parameter data of the battery is obtained and the volume change rate and expansion pressure are calculated based on these data, thereby constructing the constraints of the force safety model, thereby improving the mechanical safety of the battery during use. By dynamically monitoring the expansion pressure, the possible expansion risks of the battery can be discovered in time, reducing the calculation complexity of the force safety model, improving the accuracy of the battery safety assessment, and improving the overall safety and reliability of the battery during use.

[0058] In some embodiments, the process of establishing the thermal safety model includes: Based on the parameter data, a transient energy equation of the battery is obtained; Constructing constraints of the thermal safety model based on the transient energy equation of the battery; Based on the constraints of the thermal safety model, the thermal safety model is constructed.

[0059] It is easy to understand that when the battery is in working condition, its internal energy balance is a dynamic, multi-factor coupling process, which is mainly determined by the following three factors: the input of external heat source, the heat generated by internal chemical and electrochemical reactions, and the heat dissipation through the battery surface. This process can be described by the transient energy conservation equation, reflecting the accumulation, transfer and release of energy. The establishment process of the thermal safety model is as follows: (1) Based on the battery temperature data, battery density data, and battery energy data, the transient energy equation of the battery is as follows:

[0060] in, is the transient term of battery temperature, is the internal heat conduction term of the battery, is the temperature gradient inside the battery, is the battery temperature, is the battery density, Specific heat capacity of battery materials, is the thermal conductivity of the battery material, The heat released during the battery charging and discharging process It is the sum of heat loss caused by heat conduction, heat convection and heat radiation. Dissipates heat for the coolant.

[0061] It is easy to understand that the battery is an isothermal body. The heat conduction term inside the battery is 0. The heat loss caused by heat conduction, heat convection and heat radiation is small and can be ignored. When the battery reaches the most suitable temperature range, thermal balance needs to be maintained, that is, the heat dissipation cannot be less than the heat generation. The sign on the left side of the equation is non-negative. The coolant takes away the heat generated during the operation of the battery, maintains the temperature of the battery stable, and reduces the occurrence of thermal runaway.

[0062] (2) Based on the molar number and Faraday constant, the formula for the reversible voltage of the battery is as follows:

[0063] in, The Gibbs free energy of the reaction, is the number of moles of electrons in the reaction, is Faraday's constant, is the battery reversible voltage.

[0064] The calculation formula for the heat released by the decomposition of active materials inside the battery is as follows:

[0065] in, is the internal resistance of the battery, is the battery reversible voltage, V is the battery operating voltage, is the electrode active area, is the current density, The heat released during the battery charging and discharging process.

[0066] Based on the transient energy formula of the battery, the constraints of the thermal safety model are as follows:

[0067] in, is the internal resistance of the battery, is the battery reversible voltage, V is the battery operating voltage, is the electrode active area, is the current density, is the heat dissipation of the coolant, The heat released during the battery charging and discharging process.

[0068] (3) Construct a thermal safety model based on the constraints of the thermal safety model.

[0069] In this embodiment, by constructing a transient energy equation based on battery parameter data and further using the equation to construct constraints of a thermal safety model, accurate monitoring and evaluation of the thermal state of the battery can be achieved. By establishing constraints of the thermal safety model, the computational complexity of the thermal safety model is reduced, the accuracy of the battery thermal safety evaluation is improved, and the thermal safety and stability of the battery during use are improved.

[0070] In some embodiments, the process of establishing the voltage safety model includes: Based on the parameter data, obtaining the voltage of the battery; Constructing constraints of the voltage safety model based on the voltage of the battery; Based on the constraints of the voltage safety model, the voltage safety model is constructed.

[0071] It is easy to understand that during the operation of the battery, its voltage state has an important impact on the safety and performance of the battery. When the voltage is in extreme conditions (too high or too low), it will cause irreversible damage to the battery's electrode materials, electrolyte and overall structure, significantly reducing battery performance and increasing safety risks. Excessive voltage may cause side reactions such as decomposition of positive electrode materials and electrolyte decomposition, while releasing heat and causing thermal runaway. Excessive low voltage may cause problems such as insufficient negative electrode embedding and SEI membrane damage, causing the battery to lose some or all of its reaction ability and unable to work normally. Therefore, when the battery is running, reasonably controlling its voltage range can improve the safety and performance of the battery.

[0072] (1) Based on the parameter data, the calculation formula for the battery open circuit voltage is as follows:

[0073] in, is the open circuit voltage, is the initial open circuit voltage, are the fitting parameters, Is the battery charge state.

[0074] The calculation formula of activation polarization overpotential is as follows:

[0075] in, is the gas constant, is the exchange current density, is the number of moles of electrons in the reaction, is Faraday's constant, is the battery temperature, is the current density, is the activation polarization overpotential.

[0076] The calculation formula of concentration polarization overpotential is as follows:

[0077] in, is the maximum storage capacity of the electrode material, is the characteristic diffusion length of the electrode, is the effective diffusion coefficient, is the bulk concentration in the electrolyte liquid phase, is Faraday's constant, is the battery temperature, is the current density, is the battery charge state, is the gas constant, is the concentration polarization overpotential.

[0078] Based on the open circuit voltage, activation polarization overpotential and concentration polarization overpotential of the battery, the voltage formula of the battery is as follows:

[0079] in, is the open circuit voltage, is the activation polarization overpotential, is the concentration polarization overpotential, is the internal resistance of the battery, is the current density and V is the battery voltage.

[0080] (2) Based on the battery voltage formula, the constraints of the voltage safety model are obtained. The constraints of the voltage safety model are as follows:

[0081] in, is the minimum safe voltage of the battery. is the maximum safe voltage of the battery, and V is the battery voltage.

[0082] (3) Construct a voltage safety model based on the constraints of the voltage safety model.

[0083] In this embodiment, by calculating the battery voltage based on the battery parameter data and building the constraints of the voltage safety model based on the battery voltage, accurate monitoring and analysis of the battery voltage state can be achieved. By building the constraints of the voltage safety model, real-time voltage safety monitoring can be achieved to improve the stability and safety of battery operation.

[0084] In some embodiments, the process of establishing the mechanical-thermal-electrical safety boundary model includes: Constructing a state space of the battery based on the current density, battery temperature, and battery state of charge; Traversing all state points of the state space, and obtaining the force safety model boundary, the thermal safety model boundary, and the voltage safety model boundary based on least squares fitting; Based on the force safety model boundary, the thermal safety model boundary and the voltage safety model boundary, the safety space is obtained by the following formula:

[0085] Where j represents the current density, T represents the battery temperature, and SoC represents the battery state of charge. Represents the force safety model boundary, represents the thermal safety model boundary, represents the voltage safety model boundary, and R represents the safety space; Based on the safety space, the mechanical-thermal-electrical safety boundary model is constructed.

[0086] It is easy to understand that during the operation of the battery, the state space model of the battery is constructed based on the current density, battery temperature, and battery state of charge in order to fit the safety boundary function of the force-heat-electric safety boundary model. , by traversing all state point sets in the state space , calculate the "force-heat-electricity" value of each state point , to determine whether the battery's "power-heat-electricity" safety requirements are met. The judgment conditions are as follows:

[0087] in, represents the total expansion pressure of the battery at the i-th state point, represents the heat dissipation of the coolant at the i-th state point, represents the battery voltage at the i-th state point, Indicates the upper limit of battery expansion pressure. Indicates the upper limit of coolant heat dissipation. is the minimum safe voltage of the battery. It is the highest safe voltage of the battery.

[0088] Keep the critical point set that meets the three operating boundaries of "power-heat-electricity" , the output safety model boundary, thermal safety model boundary and voltage safety model boundary are fitted by the least squares method.

[0089] Furthermore, based on the force safety model boundary, the thermal safety model boundary and the voltage safety model boundary, the safety space is obtained by the following formula:

[0090] Where, j represents the current density, T represents the battery temperature, SOC represents the battery state of charge, Represents the force safety model boundary, represents the thermal safety model boundary, represents the voltage safety model boundary, and R represents the safety space; Figure 2 is a schematic diagram of the battery safety space provided in the embodiment of the present application. Substituting the "force-heat-electricity" safety boundary function into the three-dimensional coordinate system, the following is obtained: Figure 2 The battery operation safety range is shown. Finally, based on the safety space, a mechanical-thermal-electrical safety boundary model is constructed.

[0091] In this embodiment, by establishing a mechanical-thermal-electrical safety boundary model, the safety prediction of the battery under different operating environments can be achieved. By fitting the model boundary through the least squares method, combining factors such as current density, battery temperature and state of charge, the battery state space is constructed, and the battery safety space is evaluated based on this. By traversing the state space, the safety state of the battery under different working conditions can be judged, thereby improving the stability and safety of the battery operation.

[0092] In some embodiments, the force safety model boundary, the thermal safety model boundary, and the voltage safety model boundary may be obtained by the following formula:

[0093] Where j represents the current density, T represents the battery temperature, and SoC represents the battery state of charge. Represents the security model boundary, Represents the coefficients of the fitted function.

[0094] It is easy to understand that the safety margin function can be obtained by polynomial fitting, and the calculation formula is as follows:

[0095] Where j represents the current density, T represents the battery temperature, and SoC represents the battery state of charge. Represents the security model boundary, Represents the coefficients of the fitted function.

[0096] In this embodiment, multiple safety boundaries are fitted by the least squares method, which can intuitively describe the safe operating area under different working conditions, thereby improving the stability and safety of battery operation.

[0097] In some embodiments, the evaluating the safety of the battery based on the safety radius includes: Determine whether the safety radius is greater than a preset radius threshold; When the safety radius is less than or equal to a preset radius threshold, determining that the safety of the battery is too low, and executing a first operation, the first operation is used to stop the operation of the battery; When the safety radius is greater than a preset radius threshold, the safety of the battery is determined to be normal, and the above-mentioned steps of obtaining the operating status data of the battery are repeated. The operating status data is input into a mechanical-thermal-electrical safety boundary model to obtain a safety radius of the operating status data in a safety space.

[0098] It should be noted that the battery status is a point within the safety range. The safety radius represents the minimum distance between the current status and the safety boundary. The calculation formula of the safety radius is as follows:

[0099] in, Indicates the distance between the current state and each safety boundary. If the X state point is in the safety interval The battery safety radius is , otherwise 0.

[0100] Further, determine whether the safety radius is greater than a preset radius threshold. When the safety radius is less than or equal to the preset radius threshold, determine that the safety of the battery is too low, and execute a first operation. The first operation is used to stop the operation of the battery. When the safety radius is greater than the preset radius threshold, determine that the safety of the battery is normal. Repeat the above-mentioned acquisition of the operating status data of the battery, input the operating status data into the mechanical-thermal-electrical safety boundary model, and obtain the safety radius of the operating status data in the safety space.

[0101] In this embodiment, the evaluation result of the safety radius can be used to timely manage and respond to battery safety. Based on the comparison between the safety radius and the preset threshold, the system can judge the safety status of the battery in real time, and trigger corresponding operations when the safety radius of the battery is less than or equal to the preset threshold, thereby reducing the possibility of battery failure or accidents, improving the safety and stability of the battery during use, and reducing safety hazards caused by battery failure.

[0102] Figure 3 This is a second flow chart of a battery evaluation method based on safe area modeling provided in an embodiment of the present application, such as Figure 3 As shown, the parameter data of the battery is obtained to construct a force-heat-electric safety boundary model, and it is determined whether the battery is in an operating state. If the battery is in an operating state, the operating state data of the battery is obtained, and the operating state data is input into the force-heat-electric safety boundary model to obtain a safety radius of the operating state data in a safety space, and it is determined whether the safety radius is greater than a preset radius threshold. When the safety radius is less than or equal to the preset radius threshold, it is determined that the safety of the battery is too low, and a first operation is performed. The first operation is used to stop the operation of the battery. When the safety radius is greater than the preset radius threshold, it is determined that the safety of the battery is normal, and the above-mentioned acquisition of the operating state data of the battery is repeated, and the operating state data is input into the force-heat-electric safety boundary model to obtain a safety radius of the operating state data in a safety space.

[0103] The battery evaluation method based on safe area modeling provided in the embodiment of the present application can be executed by a battery evaluation device based on safe area modeling. In the embodiment of the present application, the battery evaluation method based on safe area modeling is executed by a battery evaluation device based on safe area modeling as an example to illustrate the battery evaluation device based on safe area modeling provided in the embodiment of the present application.

[0104] The present application also provides a battery evaluation device based on safety area modeling, such as Figure 4 As shown, the battery evaluation device based on safety area modeling includes: an acquisition module 410 , a processing module 420 and an evaluation module 440 .

[0105] An acquisition module 410 is used to acquire operating status data of the battery, wherein the operating status data includes current density, battery temperature, and battery state of charge; A processing module 420 is used to input the operating status data into a force-heat-electricity safety boundary model to obtain a safety radius of the operating status data in a safety space, wherein the force-heat-electricity safety model is a three-dimensional model constructed based on the safety space, and the safety space is a three-dimensional space composed of a force safety model boundary, a thermal safety model boundary, and a voltage safety model boundary; The evaluation module 430 is used to evaluate the safety of the battery based on the safety radius.

[0106] According to the battery assessment method based on safety area modeling provided in the embodiment of the present application, the battery operating status data is input into the force-thermal-electrical safety boundary model to obtain the safety radius of the battery operating status in the safety space. The model is constructed based on the three-dimensional safety space composed of the force safety model, the thermal safety model and the voltage safety model, and can comprehensively evaluate the safety of the battery. By analyzing the safety radius, it is possible to determine whether the current working state of the battery is in the safety area, and by real-time monitoring of changes in parameters such as current density, battery temperature, and battery state of charge, potential risk factors can be quickly identified. By combining a multi-dimensional safety model, the mutual influence of different factors is considered in the evaluation process, thereby improving the accuracy and reliability of battery safety assessment, reducing the risk of system failure or safety accidents, and effectively extending the service life of the battery. It is suitable for the entire life cycle of the battery, and the safety boundary model is simple, small in calculation, and strong in real time.

[0107] The battery evaluation device based on safe area modeling provided in the embodiment of the present application can achieve Figures 1 to 3 To avoid repetition, the various processes implemented in the embodiment of the battery assessment method based on safety area modeling are not described here.

[0108] In some embodiments, Figure 5 As shown, an embodiment of the present application also provides an electronic device 500, including a processor 501, a memory 502, and a computer program stored in the memory 502 and executable on the processor 501. When the program is executed by the processor 501, each process of the above-mentioned battery evaluation method embodiment based on safety area modeling is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be described here.

[0109] It should be noted that the electronic devices in the embodiments of the present application include the mobile electronic devices and non-mobile electronic devices mentioned above.

[0110] An embodiment of the present application also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the various processes of the above-mentioned battery evaluation method embodiment based on safety area modeling are implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0111] The processor is the processor in the electronic device in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0112] An embodiment of the present application also provides a computer program product, including a computer program, which implements the above-mentioned battery evaluation method based on safety area modeling when executed by a processor.

[0113] The processor is the processor in the electronic device in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory ROM, a random access memory RAM, a magnetic disk or an optical disk.

[0114] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, wherein the communication interface and the processor are coupled, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned battery evaluation method embodiment based on safety area modeling, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0115] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0116] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0117] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment method can be implemented by means of software plus a necessary general hardware platform, and of course it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a computer software product, which is stored in a storage medium (such as ROM / RAM, disk, CD), including a number of instructions for a terminal (which can be a mobile phone, computer, server, or network device, etc.) to execute the battery evaluation method based on safe area modeling in each embodiment of the present application.

[0118] In the description of this application, "first feature" or "second feature" may include one or more of the features.

[0119] In the description of the present application, “plurality” means two or more.

[0120] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

[0121] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", 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 this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0122] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A battery evaluation method based on safety area modeling, characterized in that: The method comprises: Acquiring operating status data of the battery, wherein the operating status data includes current density, battery temperature, and battery state of charge; The operating status data is input into a force-heat-electricity safety boundary model to obtain a safety radius of the operating status data in a safety space, wherein the force-heat-electricity safety model is a three-dimensional model constructed based on the safety space, and the safety space is a three-dimensional space composed of a force safety model boundary, a thermal safety model boundary, and a voltage safety model boundary; Based on the safety radius, the safety of the battery is evaluated.

2. The battery evaluation method based on safety area modeling according to claim 1, characterized in that: The process of establishing the force safety model includes: Obtaining parameter data of the battery, the parameter data including battery surface area, heat dissipation coefficient, internal free volume of the battery, coolant heat dissipation coefficient, and volume expansion coefficient; Based on the parameter data, obtaining a volume change rate of the battery; Obtaining an expansion pressure of the battery based on a volume change rate of the battery; Constructing constraints of the force safety model based on the expansion pressure of the battery; Based on the constraints of the force security model, the force security model is constructed.

3. The battery evaluation method based on safety area modeling according to claim 2, characterized in that: The process of establishing the thermal safety model includes: Based on the parameter data, a transient energy equation of the battery is obtained; Constructing constraints of the thermal safety model based on the transient energy equation of the battery; Based on the constraints of the thermal safety model, the thermal safety model is constructed.

4. The battery evaluation method based on safety area modeling according to claim 2, characterized in that: The process of establishing the voltage safety model includes: Based on the parameter data, obtaining the voltage of the battery; Constructing constraints of the voltage safety model based on the voltage of the battery; Based on the constraints of the voltage safety model, the voltage safety model is constructed.

5. The battery evaluation method based on safety area modeling according to claim 1, characterized in that: The process of establishing the mechanical-thermal-electrical safety boundary model includes: Constructing a state space of the battery based on the current density, battery temperature, and battery state of charge; Traversing all state points of the state space, and obtaining the force safety model boundary, the thermal safety model boundary, and the voltage safety model boundary based on least squares fitting; Based on the force safety model boundary, the thermal safety model boundary and the voltage safety model boundary, the safety space is obtained by the following formula: ； Where j represents the current density, T represents the battery temperature, and SoC represents the battery state of charge. Represents the force safety model boundary, represents the thermal safety model boundary, represents the voltage safety model boundary, and R represents the safety space; Based on the safety space, the mechanical-thermal-electrical safety boundary model is constructed.

6. The battery evaluation method based on safety area modeling according to claim 5, characterized in that: The force safety model boundary, the thermal safety model boundary and the voltage safety model boundary can be obtained by the following formula: ； Where j represents the current density, T represents the battery temperature, and SoC represents the battery state of charge. Represents the security model boundary, Represents the coefficients of the fitted function.

7. The battery evaluation method based on safe area modeling according to claim 1, characterized in that: The step of evaluating the safety of the battery based on the safety radius includes: Determine whether the safety radius is greater than a preset radius threshold; When the safety radius is less than or equal to a preset radius threshold, determining that the safety of the battery is too low, and executing a first operation, the first operation is used to stop the operation of the battery; When the safety radius is greater than a preset radius threshold, the safety of the battery is determined to be normal, and the above-mentioned steps of obtaining the operating status data of the battery are repeated. The operating status data is input into a mechanical-thermal-electrical safety boundary model to obtain a safety radius of the operating status data in a safety space.

8. A battery evaluation device based on safe area modeling, implemented by the battery evaluation method based on safe area modeling according to claim 1, characterized in that: The device comprises: An acquisition module, used to acquire the operating status data of the battery, wherein the operating status data includes current density, battery temperature, and battery state of charge; a processing module, configured to input the operating status data into a force-heat-electricity safety boundary model to obtain a safety radius of the operating status data in a safety space, wherein the force-heat-electricity safety model is a three-dimensional model constructed based on the safety space, and the safety space is a three-dimensional space composed of a force safety model boundary, a thermal safety model boundary, and a voltage safety model boundary; An evaluation module is used to evaluate the safety of the battery based on the safety radius.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the battery evaluation method based on safety area modeling according to any one of claims 1 to 7 is implemented.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the battery evaluation method based on safety area modeling according to any one of claims 1 to 7 is implemented.

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