Method and device for estimating power state of solid-state battery based on expansion stress limitation

Abstract

The invention provides a solid-state battery power state estimation method and device based on expansion stress limitation, and the method is applied to a solid-state battery, and comprises the steps: constructing an expansion strain model and an expansion stress model, and determining an equivalent stress model according to the expansion strain model, the expansion stress model and an ampere-hour integral method; based on the equivalent stress model and the equivalent circuit model, constructing an electromechanical coupling model for outputting the current expansion stress, the terminal voltage and the current SOC; determining a first current range based on the current expansion stress; a second current range based on current SOC limitation, a third current range based on terminal voltage limitation and a working current range are obtained; solving the intersection of the first current range, the second current range, the third current range and the working current range to obtain a continuous peak current estimation value; and obtaining continuous peak power based on the continuous peak current estimation value, the terminal voltage and the working power range. According to the scheme, the mechanical effect of the solid-state battery is fully considered, and the accuracy of power estimation of the solid-state battery and the safety and reliability of battery management are improved.

Description

Technical Field

[0001] This invention relates to the field of battery technology, particularly to the field of solid-state battery technology, and especially to a method and apparatus for estimating the state of power of a solid-state battery based on expansion stress limitation. Background Technology

[0002] Lithium-ion batteries have become a key research focus in the new energy field due to their outstanding advantages such as high specific energy, high specific power, high cost-effectiveness, and zero emissions. They are widely used in automobiles, drones, and aircraft, showing broad application prospects. Fully utilizing battery performance is crucial to improving the energy efficiency and reliability of fully electric vehicles. Therefore, it is essential to efficiently utilize lithium-ion batteries and maximize their performance. Real-time monitoring and management of battery status through a Battery Management System (BMS) can effectively improve battery range, reduce battery operating costs, and ensure battery safety. The core of a BMS lies in estimating the battery state, mainly including state of charge (SOC), state of health (SOH), and state of power (SOP). Among these, SOP is particularly important because it relates to the energy supply of the battery at various steady-state and dynamic operating conditions.

[0003] State of Operation (SOP) is defined as the ratio of a battery's peak power to its rated power. Peak power characterizes the battery's ultimate charge-discharge capability and relates to its energy supply under various steady-state and dynamic operating conditions. Accurate power information helps achieve proper matching of battery performance across different stages, thereby extending the vehicle's driving range. SOP is similar to engine displacement in traditional gasoline vehicles, serving as an indicator of vehicle and battery performance. However, its measurement differs from that of traditional gasoline vehicles. Because the battery's state of power is subject to various factors such as ambient temperature, operating conditions, battery charge level, and battery health, it frequently changes and cannot be directly measured; it is an implicit state variable. Therefore, estimating battery SOP remains challenging.

[0004] Solid-state batteries, as a next-generation battery technology, use solid electrolytes instead of traditional liquid electrolytes, offering advantages such as high energy density, high safety (e.g., avoiding leakage and thermal runaway), and long lifespan. Existing peak power estimation methods often rely solely on voltage and state of charge (SOC) constraints. For solid-state battery systems, their dynamic mechanical characteristics (volume changes during charging and discharging leading to mechanical stress affecting ion transport) are frequently ignored. Therefore, existing peak power estimation methods struggle to guarantee the safe use of solid-state batteries. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a method and apparatus for estimating the power state of a solid-state battery based on expansion stress constraints. This method fully considers the stress-electrochemical coupling effect of solid-state batteries, improves the accuracy of peak power estimation, and ensures the safety and reliability of solid-state batteries.

[0006] In a first aspect, embodiments of the present invention provide a method for estimating the state of power of a solid-state battery based on expansion stress constraints, applicable to solid-state batteries, including: Construct a contraction-expansion strain model and an expansion-expansion stress model, and determine the equivalent stress model based on the contraction-expansion strain model, the expansion-expansion stress model, and the ampere-hour integration method; Based on the equivalent stress model and equivalent circuit model, an electromechanical coupling model is constructed; the electromechanical coupling model is used to output the current expansion stress, terminal voltage and current SOC based on battery operating data; Based on the current expansion stress, a first current range is determined; and a second current range based on the current SOC limit, a third current range based on the terminal voltage limit, and an operating current range are obtained. The intersection of the first current range, the second current range, the third current range, and the operating current range is used to obtain the continuous peak current estimate. The continuous peak power is obtained based on the estimated continuous peak current, the terminal voltage, and the operating power range.

[0007] Secondly, embodiments of the present invention also provide a solid-state battery power state estimation device based on expansion stress limitation, comprising: A construction module is used to construct a shrinkage strain model and an expansion stress model, so as to determine the equivalent stress model based on the shrinkage strain model, the expansion stress model and the ampere-hour integration method; The coupling module is used to construct an electromechanical coupling model based on the equivalent stress model and the equivalent circuit model; the electromechanical coupling model is used to output the current expansion stress, terminal voltage and current SOC based on battery operating data; The current estimation module is used to determine a first current range based on the current expansion stress; and to obtain a second current range based on the current SOC limit, a third current range based on the terminal voltage limit, and an operating current range; and to obtain a continuous peak current estimate by finding the intersection of the first current range, the second current range, the third current range, and the operating current range. The power estimation module is used to obtain the continuous peak power based on the continuous peak current estimate, the terminal voltage, and the operating power range.

[0008] Thirdly, embodiments of the present invention also provide a computing device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, it implements the solid-state battery power state estimation method based on expansion stress limitation as described above.

[0009] Fourthly, embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to perform the solid-state battery power state estimation method based on expansion stress limitation as described above.

[0010] Fifthly, embodiments of the present invention also provide a computer program product, including computer instructions, which, when executed by a processor, implement the steps of the method described in any of the first aspects of this specification.

[0011] This invention provides a method for estimating the state of power (SOC) of a solid-state battery based on expansion stress constraints. Applied to solid-state batteries, this method constructs an electromechanical coupling model including an equivalent circuit model and an equivalent stress model. This model accurately describes the stress-electrochemical coupling effect unique to solid-state batteries, specifically the inverse effect of mechanical stress changes caused by volume variations during charging and discharging on circuit model parameters (such as internal resistance). This enables simultaneous and accurate estimation of terminal voltage, SOC, and expansion stress, thereby determining a first current range constrained by expansion stress. Then, considering multiple parameter-constrained current ranges, the intersection of these ranges is used to obtain estimates of continuous peak currents, which in turn determine the continuous peak power. Thus, by considering the impact of expansion stress caused by solid-state battery volume variations on the current, and combining this with multi-parameter-constrained current ranges, this invention achieves accurate estimation of continuous peak power, improving the safety and reliability of solid-state battery management. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a flowchart of a solid-state battery power state estimation method based on expansion stress constraint provided in an embodiment of the present invention; Figure 2 This is a second-order fractional-order equivalent circuit provided in one embodiment of the present invention; Figure 3 This is a hardware architecture diagram of a computing device provided in an embodiment of the present invention; Figure 4 This is a structural diagram of a solid-state battery power state estimation device based on expansion stress limitation, provided in an embodiment of the present invention. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0015] Solid-state batteries are an important direction for the next generation of power batteries. During operation, due to the insertion and extraction of lithium ions, the volume of the electrode will change significantly. The volume change rate of silicon-based negative electrode can reach more than 300%. This is manifested as a change in force on a macroscopic scale. In other words, solid-state batteries are always accompanied by significant mechanical effects. The state of power estimation of solid-state batteries needs to focus on their electromechanical coupling characteristics.

[0016] The following is the concept of the present invention, such as Figure 1 As shown, this embodiment of the invention provides a method for estimating the state of power of a solid-state battery based on expansion stress constraints. The method includes: Step 100: Construct a contraction strain model and an expansion stress model to determine the equivalent stress model based on the contraction strain model, the expansion stress model, and the ampere-hour integration method; Step 102: Based on the equivalent stress model and equivalent circuit model, construct an electromechanical coupling model; the electromechanical coupling model is used to output the current expansion stress, terminal voltage and current SOC based on battery operating data; Step 104: Based on the current expansion stress, determine the first current range; and obtain the second current range based on the current SOC limit, the third current range based on the terminal voltage limit, and the operating current range; Step 106: Find the intersection of the first current range, the second current range, the third current range, and the operating current range to obtain the continuous peak current estimate. Step 108: Based on the estimated continuous peak current, the terminal voltage, and the operating power range, obtain the continuous peak power.

[0017] In this embodiment of the invention, for solid-state batteries, an electromechanical coupling model including an equivalent circuit model and an equivalent stress model is constructed. This model can accurately describe the stress-electrochemical coupling effect unique to solid-state batteries, namely, the reverse influence of mechanical stress changes caused by volume changes during charging and discharging on circuit model parameters (such as internal resistance). This enables simultaneous and accurate estimation of terminal voltage, SOC, and expansion stress, thereby determining a first current range limited by expansion stress. Then, considering multiple parameter-limited current ranges, the continuous peak current estimate is obtained by finding the intersection, and thus the continuous peak power is determined. Therefore, by considering the influence of expansion stress caused by solid-state battery volume changes on the current, and combining this with a multi-parameter-limited current range, this invention achieves accurate estimation of continuous peak power, improving the safety and reliability of solid-state battery management.

[0018] The following description Figure 1 The execution method for each step is shown.

[0019] In step 100, constructing the expansion and contraction strain model and the expansion and stress model includes: A swelling and shrinkage strain model is constructed based on the swelling and shrinkage strain, SOC, and battery temperature of the solid-state battery; the swelling and shrinkage strain model is determined by the following formula: in, The expansion and contraction strain is the strain described above. The SOC deformation coefficient; Temperature coefficient; For the current SOC; This is the initial SOC; Current battery temperature; This is the initial battery temperature; An expansion stress model is constructed based on the expansion stress and contraction strain of solid-state batteries; the expansion stress model is determined by the following formula: in, The expansion stress; This refers to the battery stress coefficient. This refers to the battery expansion and contraction stress coefficient. The rate of change of the expansion stress over time; The rate of change of the expansion / contraction strain over time is given.

[0020] In step 100, the equivalent stress model is determined by the following formula: in, k For the first k Second sampling, The sampling interval; , Solid-state batteries at the 1st k +1st sampling, the first k Expansion stress during the second sampling; The first coefficient; The second coefficient; For the first k Current during the second sampling; This refers to the battery stress coefficient. This is the SOC coefficient; For the first k Battery capacity at the time of the next sampling.

[0021] It should be noted that the current at the kth sampling point is the input current of the equivalent circuit model; , SOC deformation coefficient, The coefficients of battery expansion and contraction stress can all be obtained through experimental calibration.

[0022] In this invention, the expansion and contraction strain model is used to characterize the relationship between expansion and contraction strain and SOC (State of Charge) and battery temperature; the expansion stress model is used to characterize the relationship between expansion stress and expansion and contraction strain. Specifically, regarding the mechanical effects of solid-state batteries, this invention proposes a modeling method for an equivalent stress model of solid-state batteries based on the rigid clamp assumption and the expansion and contraction properties of the battery: the mechanical effects of the solid-state battery working process are equivalent to preload. F ini and expansion force F exp The sum of these factors is used to model the macroscopic expansion effect caused by the electrode volume change due to lithium-ion migration, where the expansion force is the product of the expansion stress and the area. Since solid-state batteries exhibit insignificant temperature fluctuations during operation, this invention assumes that the temperature change of solid-state batteries is slow, and thus the expansion / contraction strain rate is expressed by the following formula: Based on the ampere-hour integration method: at this time, The input current of the equivalent circuit model; Q n Given the battery capacity, the expansion and contraction strain rate can be simplified to: Therefore, the expansion stress model can be simplified to: Where SOC coefficient ; The simplified expansion stress model is solved using zero-order preservation, assuming a sampling interval of . The discretized equivalent stress model is obtained: .

[0023] In step 102, in the electromechanical coupling model: Substituting the battery operating data and expansion stress from the previous moment into the equivalent circuit model, we obtain the SOC and terminal voltage from the previous moment. Substitute the SOC of the previous moment into the equivalent stress model to obtain the current expansion stress, and feed the current expansion stress back into the equivalent circuit model to obtain the current SOC.

[0024] In this invention, the electrical effects of solid-state batteries are captured using an equivalent circuit model. Furthermore, for the dispersion effect caused by relaxation in solid-state batteries, this invention employs a second-order fractional-order equivalent circuit for high-precision modeling, such as... Figure 2 As shown, the equivalent circuit model's terminal voltage output can be obtained as follows: in, Terminal voltage, For input current, Open circuit voltage, For ohm resistance, For the voltage of the first RCPE branch, Voltage of the second RCPE branch; expansion stress By influencing the model parameters, the terminal voltage output is affected. This couples the equivalent stress model and the equivalent circuit model, resulting in an electromechanical coupling model. In this electromechanical coupling model, the... k During the next sampling, the battery operating data from the previous moment (including input current, open-circuit voltage, etc.) and expansion stress are substituted into the equivalent circuit model to obtain the [number of samples]. k The SOC and terminal voltage were sampled the next time; then the first... k The SOC and input current of the second sample are passed to the equivalent stress model, which is based on the first sample. k The SOC, input current, and battery capacity sampled in the second sampling yielded the first... k The expansion stress is obtained from +1 sampling. Then, this cycle is repeated to obtain the terminal voltage and SOC accuracy at any sampling time.

[0025] Regarding step 104, determining the first current range based on the current expansion stress includes: Obtain the operating stress range of the solid-state battery; wherein the current expansion stress is within the operating stress range; When the current excitation is constant over several consecutive sampling periods, the equivalent stress model is modified to obtain a continuous stress model. The first current range is calculated based on the working stress range, the current expansion stress, and the continuous stress model.

[0026] In one specific implementation, determining the first current range for a single sampling period includes: calculating the first current range based on the working stress range, the current expansion stress and the continuous stress model under the single sampling period.

[0027] In a preferred embodiment, the continuous stress model is determined by the following formula: in, k For the first k Second sampling, Number of sampling periods; For solid-state batteries in continuous n Stress prediction values ​​for each sampling period; For the first k Expansion stress during the second sampling; The first coefficient; The second coefficient; C It is the third coefficient; For the first k Current during the second sampling; The first current range is determined by the following formula: in, , From the first k The second sampling to the first k+n Discharge current and charging current in the first current range during the second sampling process; , These are the minimum working stress and the maximum working stress within the stated working stress range, respectively.

[0028] In this invention, the equivalent stress model uses the sampling time as the estimation period, but the dynamic process in practical applications cannot end within one sampling period. Therefore, in order to obtain the power capability of a solid-state battery during a continuous dynamic process, it is assumed that... n × T s The excitation of the internal battery is a constant value, i.e., the input current. I [k + n ]= I [ k ], then the future continuous n Stress prediction value per sampling period Since the operating stress range of solid-state batteries needs to be maintained between the minimum and maximum operating stresses, the following constraints need to be imposed on the stress of solid-state batteries: Then, substituting these values ​​into the expression for the continuous stress model, we get: The peak current based on stress limitation can then be calculated: Since the discharge direction is defined as positive, all limits related to the peak discharge current are positive. To ensure the peak discharge current fully considers the constraints of multiple factors, the minimum value of the current limit is taken as the peak discharge current. Similarly, since the peak charging current is negative, the maximum value of each limit (i.e., the minimum absolute value) is taken as the final value. Thus, the estimated continuous peak current based on expansion stress constraints is obtained, i.e., the first current range, representing the continuous discharge and charging currents based on expansion stress constraints. n When the value is 1, it represents the peak current prediction with the sampling period as the duration.

[0029] For step 106, the estimated value of the continuous peak current is determined by the following formula: in, , From the first k The second sampling to the first k+n The charging current and discharging current of the continuous peak current estimates during the sampling process; , These are the minimum and maximum operating currents of the solid-state battery, respectively. , From the first k The second sampling to the first k+n Discharge current and charging current in the first current range during the second sampling process; , From the first k The second sampling to the first k+n The charging current and discharging current within the third current range during the second sampling process; , From the first k The second sampling to the first k+nThe charging current and discharging current of the second current range during the second sampling process.

[0030] It should be noted that the predicted values ​​of continuous peak current based on terminal voltage limitation and continuous peak current based on SOC limitation are obtained using existing technology, which will not be elaborated here.

[0031] In step 108, obtaining the continuous peak power based on the estimated continuous peak current, the terminal voltage, and the operating power range includes: Multiply the estimated continuous peak current by the terminal voltage to obtain the current power range; The continuous peak power is obtained by finding the intersection of the current power range and the operating power range; the continuous peak power is determined by the following formula: in, , These are the maximum and minimum power of the continuous peak power, respectively; , These are the maximum and minimum operating power within the operating power range, respectively. For the first k+n Terminal voltage at the time of the next sample.

[0032] In this embodiment of the invention, the continuous peak power obtained by comprehensively considering battery operating range constraints, terminal voltage constraints, SOC constraints, and expansion stress constraints is more in line with actual application scenarios, and can provide a more reasonable and efficient control strategy for vehicle energy management, maximizing the efficiency and lifespan of solid-state batteries.

[0033] like Figure 3 , Figure 4 As shown, this invention provides a solid-state battery power state estimation device based on expansion stress limitation. The device embodiment can be implemented in software, hardware, or a combination of both. From a hardware perspective, as... Figure 3 The diagram shown is a hardware architecture diagram of a computing device for a solid-state battery power state estimation device based on expansion stress limitation, provided in an embodiment of the present invention. (Except for...) Figure 3 In addition to the processor, memory, network interface, and non-volatile memory shown, the computing device in the embodiment may also include other hardware, such as a forwarding chip responsible for processing packets. Taking software implementation as an example, such as... Figure 4 As shown, a device in a logical sense is formed by the CPU of its computing device reading the corresponding computer program from non-volatile memory into memory and running it. This embodiment provides a solid-state battery power state estimation device based on expansion stress limitation, comprising: Module 400 is used to construct a contraction strain model and an expansion stress model, so as to determine the equivalent stress model based on the contraction strain model, the expansion stress model and the ampere-hour integration method; The coupling module 402 is used to construct an electromechanical coupling model based on the equivalent stress model and the equivalent circuit model; the electromechanical coupling model is used to output the current expansion stress, terminal voltage and current SOC based on battery operating data; The current estimation module 404 is used to determine a first current range based on the current expansion stress; and to obtain a second current range based on the current SOC limit, a third current range based on the terminal voltage limit, and an operating current range; and to obtain a continuous peak current estimate by finding the intersection of the first current range, the second current range, the third current range, and the operating current range. The power estimation module 406 is used to obtain the continuous peak power based on the continuous peak current estimate, the terminal voltage, and the operating power range.

[0034] In some specific implementations, the construction module 400 can be used to perform the above step 100, the coupling module 402 can be used to perform the above step 102, the current estimation module 404 can be used to perform the above steps 104 and 106, and the power estimation module 406 can be used to perform the above step 108.

[0035] In a preferred embodiment, the above-mentioned device can also be integrated with an existing battery management system (BMS) and the newly added stress sensing module and control module to form a closed-loop system. The stress sensing module is responsible for measuring the expansion stress of the solid-state battery in real time. This module uses a high-precision sensor, directly mounted on the battery surface or inside, to detect the mechanical stress caused by volume changes due to lithium-ion insertion and extraction during charging and discharging. The measurement data is converted into an electrical signal through a signal conditioning circuit and input to the control module. The control module is used to implement the methods in steps 102 to 108 above, calculating the current SOC, terminal voltage, and expansion stress in real time, and executing a continuous peak power estimation algorithm. The control module is typically implemented by a microprocessor or DSP, responsible for dynamically adjusting model parameters (such as internal resistance) and outputting continuous peak current estimates and continuous peak power. It should be noted that the stress sensing module is used to continuously detect stress and update the expansion stress in real time through an equivalent stress model.

[0036] In a more preferred embodiment, the device further includes a safety circuit for ensuring that a protection mechanism is triggered when the expansion stress exceeds the limit, such as cutting off the current or adjusting the charging and discharging strategy to prevent mechanical damage to the battery.

[0037] Since the contents of the above-described apparatus are based on the same concept as the method embodiments of the present invention, the specific contents can be found in the descriptions in the method embodiments of the present invention, and will not be repeated here.

[0038] Compared with the prior art, the advantages of this invention are: (1) This invention constructs a high-precision electromechanical coupling model with an equivalent circuit model (electrical effect) and an equivalent stress model (mechanical effect). This electromechanical coupling model can accurately describe the stress-electrochemical coupling effect unique to solid-state batteries, that is, the reverse influence of expansion stress changes on circuit model parameters (such as internal resistance), so that the model parameters can be dynamically adjusted according to stress feedback, thereby realizing the synchronous and accurate estimation of terminal voltage, SOC and expansion stress, laying the foundation for accurate peak power prediction.

[0039] (2) This invention takes expansion stress as the core constraint for estimating the peak power (SOP) of solid-state batteries and proposes a peak power estimation method based on the expansion stress constraint of solid-state batteries. Compared with traditional methods that only consider voltage and SOC limitations, this method fully considers the mechanical stress generated by volume changes during the charging and discharging process of solid-state batteries, which can effectively prevent safety problems such as battery structure damage and interface failure caused by excessive stress, and significantly improve the safety management capability of BMS.

[0040] (3) The peak power estimation method of the present invention is not only applicable to a single sampling period, but can also be extended to multiple consecutive sampling periods in the future, so as to realize the forward prediction of battery power capability under continuous dynamic operating conditions. This method integrates the dual constraints of battery constraints and expansion stress, and the peak power result obtained is more in line with the actual application scenario. It can provide a more reasonable and efficient control strategy for vehicle energy management and maximize battery efficiency and life.

[0041] (4) The hardware implementation scheme proposed in this invention provides a direct and reliable mechanical state input for the electromechanical coupling model by integrating a high-precision stress sensing module, enabling the physical realization of the peak power estimation method based on expansion stress limitation. The device has a clear structure and a high degree of modularity, and can be efficiently and reliably embedded into existing battery management systems, providing a solid hardware foundation for the safe management of solid-state batteries.

[0042] It is understood that the structures illustrated in the embodiments of the present invention do not constitute a specific limitation on a solid-state battery power state estimation device based on expansion stress limitation. In other embodiments of the present invention, a solid-state battery power state estimation device based on expansion stress limitation may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0043] The information interaction and execution process between the modules in the above-mentioned device are based on the same concept as the method embodiment of the present invention, and the specific details can be found in the description of the method embodiment of the present invention, and will not be repeated here.

[0044] This invention also provides a computing device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements a solid-state battery power state estimation method based on expansion stress limitation according to any embodiment of this invention.

[0045] This invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform a solid-state battery power state estimation method based on expansion stress limitation according to any embodiment of this invention.

[0046] Embodiments of this application also provide a computer program product, which includes a computer program. A processor of a computer device reads the computer program from a computer-readable storage medium and executes the computer program, causing the computer device to perform a solid-state battery power state estimation method based on expansion stress limitation as described in any of the above embodiments.

[0047] Specifically, a system or apparatus equipped with a storage medium may be provided, on which software program code implementing the functions of any of the embodiments described above is stored, and the computer (or CPU or MPU) of the system or apparatus may read and execute the program code stored in the storage medium.

[0048] In this case, the program code read from the storage medium can itself implement the function of any of the above embodiments, and therefore the program code and the storage medium storing the program code constitute part of the present invention.

[0049] Storage media embodiments for providing program code include floppy disks, hard disks, magneto-optical disks, optical disks (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), magnetic tapes, non-volatile memory cards, and ROMs. Alternatively, program code can be downloaded from a server computer via a communication network.

[0050] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, which can send, propagate, or transmit programs for use by or in conjunction with an instruction execution system, system, or device.

[0051] The program code contained on a computer-readable medium may be transmitted using any suitable medium, including, but not limited to, wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0052] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0053] Furthermore, it should be clear that not only can the program code read by the computer be executed, but also the operating system or other components operating on the computer can be instructed based on the program code to perform some or all of the actual operations, thereby realizing the function of any of the embodiments described above.

[0054] Furthermore, it is understood that the program code read from the storage medium is written to the memory set in the expansion board inserted into the computer or to the memory set in the expansion module connected to the computer. Then, based on the instructions of the program code, the CPU or other components installed on the expansion board or expansion module execute some and all of the actual operations, thereby realizing the function of any of the above embodiments.

[0055] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0056] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as ROM, RAM, magnetic disk, or optical disk.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for estimating the state of power of a solid-state battery based on expansion stress constraints, characterized in that, Applications in solid-state batteries include: Construct a contraction-expansion strain model and an expansion-expansion stress model, and determine the equivalent stress model based on the contraction-expansion strain model, the expansion-expansion stress model, and the ampere-hour integration method; Based on the equivalent stress model and equivalent circuit model, an electromechanical coupling model is constructed; the electromechanical coupling model is used to output the current expansion stress, terminal voltage and current SOC based on battery operating data; Based on the current expansion stress, a first current range is determined; and a second current range based on the current SOC limit, a third current range based on the terminal voltage limit, and an operating current range are obtained. The intersection of the first current range, the second current range, the third current range, and the operating current range is used to obtain the continuous peak current estimate. The continuous peak power is obtained based on the estimated continuous peak current, the terminal voltage, and the operating power range.

2. The method according to claim 1, characterized in that, The construction of the expansion and contraction strain model and the expansion stress model includes: A swelling and shrinkage strain model is constructed based on the swelling and shrinkage strain, SOC, and battery temperature of the solid-state battery; the swelling and shrinkage strain model is determined by the following formula: in, The expansion and contraction strain is the strain described above. The SOC deformation coefficient; Temperature coefficient; For the current SOC; This is the initial SOC; Current battery temperature; This is the initial battery temperature; An expansion stress model is constructed based on the expansion stress and contraction strain of solid-state batteries; the expansion stress model is determined by the following formula: in, The expansion stress; This refers to the battery stress coefficient. This is the battery expansion and contraction stress coefficient.

3. The method according to claim 1, characterized in that, The equivalent stress model is determined by the following formula: in, k For the first k Second sampling, The sampling interval; , Solid-state batteries at the 1st k +1st sampling, the first k Expansion stress during the second sampling; The first coefficient; The second coefficient; For the first k Current during the second sampling; This refers to the battery stress coefficient. This is the SOC coefficient; For the first k Battery capacity at the time of the next sampling; And / or, In the electromechanical coupling model: Substituting the battery operating data and expansion stress from the previous moment into the equivalent circuit model, we obtain the SOC and terminal voltage from the previous moment. Substitute the SOC of the previous moment into the equivalent stress model to obtain the current expansion stress, and feed the current expansion stress back into the equivalent circuit model to obtain the current SOC.

4. The method according to claim 1, characterized in that, Determining the first current range based on the current expansion stress includes: Obtain the operating stress range of the solid-state battery; wherein the current expansion stress is within the operating stress range; When the current excitation is constant over several consecutive sampling periods, the equivalent stress model is modified to obtain a continuous stress model. The first current range is calculated based on the working stress range, the current expansion stress, and the continuous stress model; Preferably, the continuous stress model is determined by the following formula: in, k For the first k Second sampling, Number of sampling periods; For solid-state batteries in continuous n Stress prediction values ​​for each sampling period; For the first k Expansion stress during the second sampling; The first coefficient; The second coefficient; C It is the third coefficient; For the first k Current during the second sampling; The first current range is determined by the following formula: in, , From the first k The second sampling to the first k+n Discharge current and charging current in the first current range during the second sampling process; , These are the minimum working stress and the maximum working stress within the stated working stress range, respectively.

5. The method according to claim 1, characterized in that, The estimated value of the continuous peak current is determined by the following formula: in, , From the first k The second sampling to the first k+n The charging current and discharging current of the continuous peak current estimates during the sampling process; , These are the minimum and maximum operating currents of the solid-state battery, respectively. , From the first k The second sampling to the first k+n Discharge current and charging current in the first current range during the second sampling process; , From the first k The second sampling to the first k+n The charging current and discharging current within the third current range during the second sampling process; , From the first k The second sampling to the first k+n The charging current and discharging current of the second current range during the second sampling process.

6. The method according to any one of claims 1 to 5, characterized in that, The process of obtaining the continuous peak power based on the estimated continuous peak current, the terminal voltage, and the operating power range includes: Multiply the estimated continuous peak current by the terminal voltage to obtain the current power range; The continuous peak power is obtained by finding the intersection of the current power range and the operating power range.

7. A power state estimation device for solid-state batteries based on expansion stress constraint, characterized in that, include: A construction module is used to construct a shrinkage strain model and an expansion stress model, so as to determine the equivalent stress model based on the shrinkage strain model, the expansion stress model and the ampere-hour integration method; The coupling module is used to construct an electromechanical coupling model based on the equivalent stress model and the equivalent circuit model. The electromechanical coupling model is used to output the current expansion stress, terminal voltage, and current SOC based on battery operating data; A current estimation module is used to determine a first current range based on the current expansion stress; And obtain a second current range based on the current SOC limit, a third current range based on the terminal voltage limit, and an operating current range; and find the intersection of the first current range, the second current range, the third current range, and the operating current range to obtain a continuous peak current estimate. The power estimation module is used to obtain the continuous peak power based on the continuous peak current estimate, the terminal voltage, and the operating power range.

8. A computing device comprising a memory and a processor, wherein the memory stores a computer program, and the processor, when executing the computer program, implements the method as described in any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to perform the method of any one of claims 1-6.

10. A computer program product, characterized in that, It includes computer instructions that, when executed by a processor, implement the steps of the method as described in any one of claims 1-6.

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