Lithium plating detection method and apparatus for lithium-ion battery, computer device, readable storage medium, and program product

Abstract

The present application relates to the technical field of battery detection, and to a lithium plating detection method and apparatus for a lithium-ion battery, a device, a storage medium, and a program product. The method can improve the accuracy of lithium plating detection. The method comprises: constructing a lithium plating electrochemical model on the basis of electrochemical parameters of a lithium-ion battery, constructing a lithium plating thermal model on the basis of thermal parameters of the lithium-ion battery, and constructing a lithium plating strain model on the basis of geometric parameters of the lithium-ion battery; coupling the lithium plating electrochemical model with the lithium plating thermal model, and coupling the lithium plating electrochemical model with the lithium plating strain model, to obtain an electrochemical-thermal-stress coupled model; acquiring target characteristic parameter values of the lithium-ion battery when lithium plating occurs, and setting lithium plating threshold conditions on the basis of the target characteristic parameter values; and acquiring current characteristic parameter values of the lithium-ion battery by means of the electrochemical-thermal-stress coupled model, and on the basis of the current characteristic parameter values and the lithium plating threshold conditions, detecting whether lithium plating occurs in the lithium-ion battery.

Description

Methods, apparatus, computer equipment, readable storage media and program products for lithium-ion battery lithium plating detection Technical Field

[0001] This application relates to the field of battery testing technology, and in particular to a method, apparatus, computer equipment, computer-readable storage medium, and computer program product for detecting lithium plating in lithium-ion batteries. Background Technology

[0002] With the development of energy storage technology, electrochemical energy storage technology has emerged. Lithium-ion battery energy storage is the core of electrochemical energy storage. Lithium-ion batteries have technical advantages such as high power, high energy density, long cycle life, no memory effect, and no pollution. Lithium-ion batteries exhibit good electrochemical performance under normal operating conditions, but under extreme conditions such as overcharging, low-temperature charging, and fast charging, lithium plating is prone to occur.

[0003] Traditional technologies primarily rely on in-situ detection methods to detect lithium plating in lithium-ion batteries. These methods often use the shape of the battery's internal resistance distribution curve during intermittent charging and a data relationship model between the degree of lithium plating and the internal resistance value to determine the extent of plating. However, these methods require specific intermittent charging conditions and cannot detect lithium plating behavior in real time, limiting their applicability. Relying solely on the shape of the internal resistance distribution curve makes it difficult to accurately quantify the degree and location of lithium plating. Furthermore, changes in internal resistance are not the only influencing factor for lithium plating; other factors (such as temperature changes) can also cause changes in internal resistance, leading to misjudgments and resulting in low accuracy in lithium plating detection using traditional technologies. Summary of the Invention

[0004] Therefore, it is necessary to provide a method, apparatus, computer equipment, computer-readable storage medium, and computer program product for detecting lithium plating in lithium-ion batteries, in order to address the above-mentioned technical problems.

[0005] In a first aspect, this application provides a method for detecting lithium plating in lithium-ion batteries, comprising:

[0006] Identify the lithium-ion battery to be tested and obtain its battery parameters; the battery parameters include electrochemical parameters, thermal parameters, and geometric parameters.

[0007] Based on the electrochemical parameters, a lithium plating electrochemical model of the lithium-ion battery is constructed; based on the thermal parameters, a lithium plating thermal model of the lithium-ion battery is constructed; and based on the geometric parameters, a lithium plating strain model of the lithium-ion battery is constructed.

[0008] The lithium plating electrochemical model is coupled with the lithium plating thermal model, and the lithium plating electrochemical model is coupled with the lithium plating strain model to obtain the electrochemical-thermal-stress coupled model of the lithium-ion battery.

[0009] The lithium plating phenomenon of the lithium-ion battery is simulated using a lithium plating simulation system to obtain the target characteristic parameter value of the lithium-ion battery when the lithium plating phenomenon occurs, and the lithium plating threshold condition is set according to the target characteristic parameter value.

[0010] The current characteristic parameter values ​​of the lithium-ion battery are obtained using the electrochemical-thermal-stress coupling model. Based on the current characteristic parameter values ​​and the lithium plating threshold condition, it is detected whether the lithium-ion battery has undergone lithium plating.

[0011] In one embodiment, coupling the lithium plating electrochemical model with the lithium plating thermal model, and coupling the lithium plating electrochemical model with the lithium plating strain model, includes:

[0012] The heat generation rate of the lithium-ion battery is calculated using the lithium plating electrochemical model. Based on the heat generation rate, a heat generation rate plane is obtained. This heat generation rate plane is used as the heat source term of the lithium plating thermal model to calculate the temperature of the internal temperature field in the lithium-ion battery. Based on the temperature, a temperature distribution plane is obtained. This temperature distribution plane is used as the temperature term of the lithium plating electrochemical model. The lithium ion concentration of the lithium plating side reaction in the lithium-ion battery is calculated using the lithium plating electrochemical model. Based on the lithium ion concentration, a lithium ion concentration distribution plane is obtained. This lithium ion concentration distribution plane is used as the input term of the lithium plating strain model.

[0013] In one embodiment, before obtaining the current characteristic parameter values ​​of the lithium-ion battery using the electrochemical-thermal-stress coupling model, the method further includes: obtaining temperature data and strain data of the lithium-ion battery collected by a fiber Bragg grating device;

[0014] The step of obtaining the current characteristic parameter values ​​of the lithium-ion battery using the electrochemical-thermal-stress coupling model includes: inputting the temperature data and the strain data into the electrochemical-thermal-stress coupling model for numerical calculation and data fitting, and obtaining the current characteristic parameter values ​​output by the electrochemical-thermal-stress coupling model.

[0015] In one embodiment, detecting whether the lithium-ion battery has undergone lithium plating based on the current characteristic parameter value and the lithium plating threshold condition includes:

[0016] Determine whether the current characteristic parameter value meets the lithium plating threshold condition; if the current characteristic parameter value meets the lithium plating threshold condition, confirm that the lithium-ion battery has undergone lithium plating and trigger an early warning signal; if the current characteristic parameter value does not meet the lithium plating threshold condition, confirm that the lithium-ion battery has not undergone lithium plating.

[0017] In one embodiment, constructing a lithium-ion battery electrochemical model based on the electrochemical parameters includes:

[0018] Under the premise that the lithium-ion battery meets the preset assumptions, lithium plating kinetic parameters are added to the negative electrode of the lithium-ion battery according to the electrochemical parameters; based on the lithium plating kinetic parameters, a charge conservation sub-model, a mass conservation sub-model, and an electrode kinetic sub-model of the lithium-ion battery are constructed as the lithium plating electrochemical model.

[0019] In one embodiment, constructing the lithium plating thermal model of the lithium-ion battery based on the thermal parameters includes:

[0020] Based on the thermal parameters, the heat source items in the lithium-ion battery are determined; the heat source items include polarization heat, ohmic heat, and reaction heat; the total heat generated by the lithium-ion battery is obtained based on the sum of the heat generated by the heat source items; the total flow heat transfer between the surface of the lithium-ion battery and the air is obtained, and the lithium plating heat model is constructed based on the total heat and the total flow heat transfer.

[0021] Secondly, this application also provides a lithium plating detection device for lithium-ion batteries, comprising:

[0022] The parameter acquisition module is used to identify the lithium-ion battery to be tested and acquire the battery parameters of the lithium-ion battery; the battery parameters include electrochemical parameters, thermal parameters and geometric parameters;

[0023] The model building module is used to build a lithium plating electrochemical model of the lithium-ion battery based on the electrochemical parameters, a lithium plating thermal model of the lithium-ion battery based on the thermal parameters, and a lithium plating strain model of the lithium-ion battery based on the geometric parameters.

[0024] The model coupling module is used to couple the lithium plating electrochemical model with the lithium plating thermal model, and to couple the lithium plating electrochemical model with the lithium plating strain model, to obtain the electrochemical-thermal-stress coupling model of the lithium-ion battery;

[0025] The lithium plating simulation module is used to simulate the lithium plating phenomenon of the lithium-ion battery using a lithium plating simulation system, so as to obtain the target characteristic parameter value of the lithium-ion battery when the lithium plating phenomenon occurs, and set the lithium plating threshold condition according to the target characteristic parameter value.

[0026] The lithium plating detection module is used to obtain the current characteristic parameter values ​​of the lithium-ion battery using the electrochemical-thermal-stress coupling model, and to detect whether the lithium-ion battery has undergone lithium plating based on the current characteristic parameter values ​​and the lithium plating threshold condition.

[0027] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0028] The lithium-ion battery to be tested is identified, and its battery parameters are obtained. These parameters include electrochemical parameters, thermal parameters, and geometric parameters. Based on the electrochemical parameters, a lithium plating electrochemical model is constructed; based on the thermal parameters, a lithium plating thermal model is constructed; and based on the geometric parameters, a lithium plating strain model is constructed. The lithium plating electrochemical model and the lithium plating thermal model are coupled, and the lithium plating electrochemical model and the lithium plating strain model are coupled to obtain an electrochemical-thermal-stress coupled model of the lithium-ion battery. The lithium plating phenomenon of the lithium-ion battery is simulated using a lithium plating simulation system to obtain the target characteristic parameter values ​​of the lithium-ion battery when lithium plating occurs. Based on the target characteristic parameter values, a lithium plating threshold condition is set. Using the electrochemical-thermal-stress coupled model, the current characteristic parameter values ​​of the lithium-ion battery are obtained. Based on the current characteristic parameter values ​​and the lithium plating threshold condition, it is detected whether the lithium-ion battery has experienced lithium plating.

[0029] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the following steps:

[0030] The lithium-ion battery to be tested is identified, and its battery parameters are obtained. These parameters include electrochemical parameters, thermal parameters, and geometric parameters. Based on the electrochemical parameters, a lithium plating electrochemical model is constructed; based on the thermal parameters, a lithium plating thermal model is constructed; and based on the geometric parameters, a lithium plating strain model is constructed. The lithium plating electrochemical model and the lithium plating thermal model are coupled, and the lithium plating electrochemical model and the lithium plating strain model are coupled to obtain an electrochemical-thermal-stress coupled model of the lithium-ion battery. The lithium plating phenomenon of the lithium-ion battery is simulated using a lithium plating simulation system to obtain the target characteristic parameter values ​​of the lithium-ion battery when lithium plating occurs. Based on the target characteristic parameter values, a lithium plating threshold condition is set. Using the electrochemical-thermal-stress coupled model, the current characteristic parameter values ​​of the lithium-ion battery are obtained. Based on the current characteristic parameter values ​​and the lithium plating threshold condition, it is detected whether the lithium-ion battery has experienced lithium plating.

[0031] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, performs the following steps:

[0032] The lithium-ion battery to be tested is identified, and its battery parameters are obtained. These parameters include electrochemical parameters, thermal parameters, and geometric parameters. Based on the electrochemical parameters, a lithium plating electrochemical model is constructed; based on the thermal parameters, a lithium plating thermal model is constructed; and based on the geometric parameters, a lithium plating strain model is constructed. The lithium plating electrochemical model and the lithium plating thermal model are coupled, and the lithium plating electrochemical model and the lithium plating strain model are coupled to obtain an electrochemical-thermal-stress coupled model of the lithium-ion battery. The lithium plating phenomenon of the lithium-ion battery is simulated using a lithium plating simulation system to obtain the target characteristic parameter values ​​of the lithium-ion battery when lithium plating occurs. Based on the target characteristic parameter values, a lithium plating threshold condition is set. Using the electrochemical-thermal-stress coupled model, the current characteristic parameter values ​​of the lithium-ion battery are obtained. Based on the current characteristic parameter values ​​and the lithium plating threshold condition, it is detected whether the lithium-ion battery has experienced lithium plating.

[0033] The aforementioned lithium plating detection method, apparatus, computer equipment, computer-readable storage medium, and computer program products for lithium-ion batteries construct lithium plating electrochemical models, lithium plating thermal models, and lithium plating strain models based on the electrochemical, thermal, and geometric parameters of the lithium-ion battery. The lithium plating electrochemical model is coupled with the lithium plating thermal model, and the lithium plating electrochemical model is coupled with the lithium plating strain model to construct an electrochemical-thermal-stress coupled model for the lithium-ion battery. This unifies the electrochemical behavior, thermal effect, and strain effect of the lithium-ion battery into a single mathematical model. By comprehensively detecting multiple characteristic parameters such as electrochemistry, heat, and stress, the degree of lithium plating can be accurately quantified, and the area where lithium plating occurs can be accurately located, avoiding misjudgments and omissions, thereby improving the accuracy of lithium plating detection. Furthermore, this solution can monitor lithium plating in real time during the operation of lithium-ion batteries (including charging, discharging, or resting conditions), without relying on intermittent testing or specific experimental conditions. It can also be adapted to different types of lithium-ion battery systems (including different electrolytes, positive and negative electrode materials, etc.) and is not significantly affected by external environments (such as temperature, vibration, etc.). It can accurately detect lithium plating behavior under extreme conditions such as high-rate charging, low-temperature charging, and overcharging. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 shows the application environment of a lithium-ion battery lithium plating detection method in one embodiment;

[0036] Figure 2 is a flowchart illustrating a lithium plating detection method for lithium-ion batteries in one embodiment.

[0037] Figure 3 is a flowchart illustrating the model coupling steps in one embodiment;

[0038] Figure 4 is a flowchart illustrating a lithium plating detection method for lithium-ion batteries in a specific embodiment.

[0039] Figure 5 is a structural block diagram of a lithium-ion battery lithium plating detection device in one embodiment;

[0040] Figure 6 is an internal structure diagram of a computer device in one embodiment. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0042] The lithium plating detection method for lithium-ion batteries provided in this application embodiment can be applied to the application environment shown in Figure 1. The terminal communicates with the server via a network. The data storage system can store the data that the server needs to process. The data storage system can be integrated on the server, or it can be located in the cloud or on another network server.

[0043] Specifically, the lithium plating detection method for lithium-ion batteries provided in this application embodiment can be executed by a terminal.

[0044] For example, the terminal identifies the lithium-ion battery to be tested and obtains its battery parameters, including electrochemical, thermal, and geometric parameters. Based on the electrochemical parameters, the terminal constructs a lithium-ion battery electrochemical model for lithium plating, a lithium-ion battery thermal model for lithium plating based on the thermal parameters, and a lithium-ion battery strain model for lithium plating based on the geometric parameters. The terminal couples the lithium plating electrochemical model with the lithium plating thermal model and with the lithium plating strain model to obtain an electrochemical-thermal-stress coupled model for the lithium-ion battery. The terminal uses a lithium plating simulation system to simulate the lithium plating phenomenon of the lithium-ion battery to obtain the target characteristic parameter values ​​when lithium plating occurs, and sets lithium plating threshold conditions based on the target characteristic parameter values. The terminal uses the electrochemical-thermal-stress coupled model to obtain the current characteristic parameter values ​​of the lithium-ion battery, and detects whether lithium plating has occurred based on the current characteristic parameter values ​​and the lithium plating threshold conditions.

[0045] In the application environment shown in Figure 1, the terminal can be, but is not limited to, various personal computers, laptops, smartphones, and tablets. The server can be implemented using a standalone server or a server cluster consisting of multiple servers.

[0046] In one embodiment, as shown in Figure 2, a lithium plating detection method for lithium-ion batteries is provided. Taking the application of this method to the terminal in Figure 1 as an example, the method includes the following steps:

[0047] Step S201: Determine the lithium-ion battery to be tested and obtain the battery parameters of the lithium-ion battery; the battery parameters include electrochemical parameters, thermal parameters and geometric parameters.

[0048] Among them, electrochemical parameters include the concentration, volume fraction, diffusion coefficient, conductivity, radius of porous electrode particles, and lithium-ion concentration of the battery electrode material; thermal parameters include the specific heat capacity, thermal conductivity, and density of the battery; and geometric parameters include the width, thickness, and height of the battery, as well as the width, thickness, height, and tab position of each layer in the basic electrochemical unit.

[0049] Specifically, the terminal responds to the lithium plating detection command of the lithium-ion battery, determines the lithium-ion battery to be tested according to the command, and obtains the battery parameters of the lithium-ion battery.

[0050] Step S202: Based on electrochemical parameters, construct an electrochemical model for lithium-ion battery deposition; based on thermal parameters, construct a thermal model for lithium-ion battery deposition; and based on geometric parameters, construct a strain model for lithium-ion battery deposition.

[0051] The lithium plating electrochemical model includes a charge conservation sub-model, a mass conservation sub-model, and an electrode kinetics sub-model.

[0052] Specifically, firstly, under the premise that the lithium-ion battery meets the preset assumptions, the terminal adds lithium plating kinetic parameters to the negative electrode of the lithium-ion battery based on electrochemical parameters, and constructs a charge conservation sub-model, a mass conservation sub-model, and an electrode kinetic sub-model of the lithium-ion battery based on the lithium plating kinetic parameters, as the lithium plating electrochemical model; then, the terminal determines the heat source terms in the lithium-ion battery based on thermal parameters, obtains the total heat generated by the lithium-ion battery based on the sum of the heat generation of the heat source terms, and constructs a lithium plating thermal model based on the total heat and the total flow heat transfer; finally, the terminal constructs a lithium plating strain model of the lithium-ion battery based on geometric parameters.

[0053] To further explain, constructing a lithium-ion battery strain model specifically includes the following steps:

[0054] When lithium ions diffuse into the spherical particles of the negative electrode and some lithium ions are deposited on the surface of the negative electrode particles, the particles expand and deform. The "Solid Mechanics" module of simulation software such as COMSOL can be used to build a lithium plating strain model to simulate the volume expansion caused by lithium plating and its impact on the stress distribution of the battery casing. The expression is as follows:

[0055]

[0056] In the above formula, ε r and ε θ These are radial strain and circumferential strain, respectively; σ r and σ θ These are radial stress and circumferential stress, respectively; Δc s =c s-c0, where c0 is the initial lithium-ion concentration; E is the elastic modulus; v is Poisson's ratio; and Ω is the partial molar volume.

[0057] The geometric equation is:

[0058]

[0059] In the above formula, u is the radial displacement.

[0060] Assuming there are no body forces acting on the negative electrode spherical particle, the mechanical equilibrium equation is:

[0061]

[0062] To quickly identify the critical area for negative electrode particle damage during lithium-ion charging and discharging, the following VonMises stress is introduced:

[0063] σ e =|σ r -σ θ |

[0064] Step S203: Couple the lithium plating electrochemical model with the lithium plating thermal model, and couple the lithium plating electrochemical model with the lithium plating strain model to obtain the electrochemical-thermal-stress coupling model of the lithium-ion battery.

[0065] Specifically, the terminal uses a lithium plating electrochemical model to calculate the heat generation rate of the lithium-ion battery. Based on the heat generation rate, a heat generation rate plane is obtained. This plane is used as the heat source term of the lithium plating thermal model to calculate the temperature of the internal temperature field in the lithium-ion battery. Then, based on the temperature, a temperature distribution plane is obtained. This plane is used as the temperature term of the lithium plating electrochemical model. Finally, the lithium-ion concentration of the lithium plating side reaction in the lithium-ion battery is calculated using the lithium plating electrochemical model. Based on the lithium-ion concentration, a lithium-ion concentration distribution plane is obtained. This plane is used as the input term of the lithium plating strain model to obtain the electrochemical-thermal-stress coupling model of the lithium-ion battery.

[0066] Step S204: Simulate the lithium plating phenomenon of lithium-ion batteries using a lithium plating simulation system to obtain the target characteristic parameter values ​​of lithium-ion batteries when lithium plating occurs, and set lithium plating threshold conditions based on the target characteristic parameter values.

[0067] Among them, the target characteristic parameter values ​​can be the negative electrode potential, lithium plating current density, lithium plating amount, thermal effect, and stress and strain data of the lithium-ion battery when lithium plating occurs.

[0068] Specifically, the terminal constructs a lithium plating simulation system, which is used to simulate the lithium plating behavior of lithium-ion batteries under different operating conditions (high-rate charging, low-temperature charging, or overcharging), record the corresponding data, obtain the target characteristic parameter values ​​of lithium-ion batteries when lithium plating occurs, and set the corresponding lithium plating threshold conditions based on the target characteristic parameter values.

[0069] To further explain, the construction of the lithium plating simulation system includes the following steps:

[0070] Simulate the lithium plating behavior of lithium-ion batteries under different operating conditions (high-rate charging, low-temperature charging, or overcharging) and record the corresponding data.

[0071] Monitoring of negative electrode potential includes:

[0072] The distribution of the negative electrode potential is output in the model. Post-processing analysis of the negative electrode potential distribution was used to check for any issues. If a negative value appears in the specified area, the location and range of that area are recorded.

[0073] The calculation of lithium plating current density includes:

[0074] Calculate the current density j2 of the lithium plating side reaction and the exchange current density j of the lithium plating reaction. 0,2 The lithium plating current density was recorded as a function of time and location.

[0075] Record areas with high lithium plating current density (such as electrode edges or locations with concentrated current density). The calculation of the amount of lithium plating includes:

[0076] The formula for calculating the amount of lithium plating is defined, with the time integral of the lithium plating current density as the variable. The equation is as follows:

[0077]

[0078] In the above formula, m Li Let A be the amount of metallic lithium produced by lithium plating, A be the surface area of ​​the electrode, n be the number of electrons in the lithium plating reaction, and F be the Faraday constant.

[0079] Outputs lithium plating distribution maps, showing the amount of lithium plating at various locations on the electrode surface; outputs cumulative lithium plating curves, showing the increasing trend of lithium plating over time; thermal effect analysis, including: outputting temperature distribution maps, showing the temperature rise in the lithium plating area; analyzing local hot spots caused by the heat of lithium plating reaction; stress and strain data, including: strain distribution of the battery casing, with abnormal casing strain (such as local expansion) serving as indirect evidence of lithium plating; local mechanical stress distribution, with areas of localized stress concentration being high-risk locations for lithium plating, which can be used for detection and localization.

[0080] Based on the above analysis of the lithium plating reaction, data on the negative electrode potential, lithium plating current density, lithium plating amount, thermal effect, and stress and strain during lithium plating are obtained. These data serve as early warning indicators and a basis for detecting the location of lithium plating, including: overpotential increase, localized temperature anomalies, casing strain or mechanical stress concentration, high negative electrode surface current density, and localized temperature rise. Corresponding thresholds are set; when these thresholds are exceeded, a warning signal is triggered.

[0081] Step S205: Using the electrochemical-thermal-stress coupling model, obtain the current characteristic parameter values ​​of the lithium-ion battery, and detect whether lithium plating occurs in the lithium-ion battery based on the current characteristic parameter values ​​and the lithium plating threshold condition.

[0082] Among them, the current characteristic parameter values ​​can be the current negative electrode potential, lithium plating current density, lithium plating amount, thermal effect, and stress and strain data of the lithium-ion battery.

[0083] Specifically, the terminal inputs the temperature and strain data of the lithium-ion battery into the electrochemical-thermal-stress coupling model for numerical calculation and data fitting to obtain the current characteristic parameter values ​​output by the electrochemical-thermal-stress coupling model. Then, it determines whether the current characteristic parameter values ​​meet the lithium plating threshold condition. If the current characteristic parameter values ​​meet the lithium plating threshold condition, it is confirmed that lithium plating has occurred in the lithium-ion battery, and an early warning signal is triggered. If the current characteristic parameter values ​​do not meet the lithium plating threshold condition, it is confirmed that lithium plating has not occurred in the lithium-ion battery.

[0084] In the aforementioned lithium plating detection method for lithium-ion batteries, based on the electrochemical, thermal, and geometric parameters of the lithium-ion battery, an electrochemical model, a thermal model, and a strain model for lithium plating are constructed. The electrochemical model and the thermal model are coupled, and the electrochemical model and the strain model are coupled to construct an electrochemical-thermal-stress coupled model for the lithium-ion battery. This unifies the electrochemical behavior, thermal effect, and strain effect of the lithium-ion battery into a single mathematical model. By comprehensively detecting multiple characteristic parameters such as electrochemistry, heat, and stress, the degree of lithium plating can be accurately quantified, and the area where lithium plating occurs can be accurately located, avoiding misjudgment and missed detection, thereby improving the accuracy of lithium plating detection. Furthermore, this solution can monitor lithium plating in real time during the operation of lithium-ion batteries (including charging, discharging, or resting conditions), without relying on intermittent testing or specific experimental conditions. It can also be adapted to different types of lithium-ion battery systems (including different electrolytes, positive and negative electrode materials, etc.) and is not significantly affected by external environmental factors (such as temperature, vibration, etc.). It can accurately detect lithium plating behavior under extreme conditions such as high-rate charging, low-temperature charging, and overcharging.

[0085] In one embodiment, as shown in FIG3, step S203 above, coupling the lithium plating electrochemical model with the lithium plating thermal model, and coupling the lithium plating electrochemical model with the lithium plating strain model, specifically includes the following steps:

[0086] Step S301: Calculate the heat generation rate of the lithium-ion battery using the lithium plating electrochemical model. Based on the heat generation rate, obtain the heat generation rate plane. Use the heat generation rate plane as the heat source term of the lithium plating thermal model to calculate the temperature of the internal temperature field in the lithium-ion battery.

[0087] Step S302: Based on the temperature, obtain the temperature distribution plane and use the temperature distribution plane as the temperature term in the lithium plating electrochemical model.

[0088] Step S303: Calculate the lithium ion concentration of the lithium plating side reaction in the lithium-ion battery using the lithium plating electrochemical model. Based on the lithium ion concentration, obtain the lithium ion concentration distribution plane and use it as the input of the lithium plating strain model.

[0089] Specifically, the terminal integrates the heat generation rate calculated by the lithium plating electrochemical model along the battery thickness direction and calculates the average value to obtain a two-dimensional heat generation rate plane. This two-dimensional heat generation rate plane is then input into the lithium plating thermal model as the heat source term, thus completing the coupling of the heat generation rate from the lithium plating electrochemical model to the lithium plating thermal model. Next, the terminal integrates the temperature calculated by the lithium plating thermal model along the battery thickness direction and calculates the average value to obtain a two-dimensional temperature distribution plane. This two-dimensional temperature distribution plane is then input into the lithium plating electrochemical model as... The temperature term of the lithium plating electrochemical model is introduced, thus completing the coupling of the heat generation rate from the lithium plating electrochemical model to the lithium plating thermal model. Finally, the lithium ion concentration of the lithium plating side reaction in the lithium plating electrochemical model is integrated and the average value is calculated to obtain a two-dimensional lithium ion concentration distribution plane. This two-dimensional lithium ion concentration distribution plane is input into the lithium plating strain model as an input term, thus completing the coupling of lithium ion concentration from the lithium plating electrochemical model to the lithium plating strain model. This accurately constructs the electrochemical-thermal-stress coupling model of the lithium-ion battery.

[0090] In one embodiment, before obtaining the current characteristic parameter values ​​of the lithium-ion battery using the electrochemical-thermal-stress coupling model, the following steps are also included:

[0091] Acquire temperature and strain data of lithium-ion batteries obtained by fiber Bragg grating equipment;

[0092] In step S205 above, the current characteristic parameter values ​​of the lithium-ion battery are obtained using the electrochemical-thermal-stress coupling model, specifically including the following steps:

[0093] Temperature and strain data are input into the electrochemical-thermal-stress coupling model for numerical calculation and data fitting to obtain the current characteristic parameter values ​​output by the electrochemical-thermal-stress coupling model.

[0094] Specifically, the terminal uses fiber Bragg grating equipment to collect temperature and strain data of lithium-ion batteries. Fiber optics are arranged on the surface of the lithium-ion batteries, focusing on hot spots such as the center of the battery surface (heat concentration area) and corner areas. The collected temperature and strain data are input into an electrochemical-thermal-stress coupling model. Through numerical calculation and data fitting, current characteristic parameters related to lithium plating are extracted, including negative electrode potential, lithium plating current density, lithium plating amount, and lithium plating location.

[0095] In one embodiment, step S205 above, which detects whether lithium plating has occurred in the lithium-ion battery based on the current characteristic parameter value and the lithium plating threshold condition, specifically includes the following steps:

[0096] Determine whether the current characteristic parameter value meets the lithium plating threshold condition; if the current characteristic parameter value meets the lithium plating threshold condition, it is confirmed that lithium plating has occurred in the lithium-ion battery, and an early warning signal is triggered; if the current characteristic parameter value does not meet the lithium plating threshold condition, it is confirmed that lithium plating has not occurred in the lithium-ion battery.

[0097] Specifically, the terminal detects whether lithium-ion batteries have undergone lithium plating by determining whether the current characteristic parameter value meets the lithium plating threshold condition. If the current characteristic parameter value meets the lithium plating threshold condition, it confirms that lithium-ion batteries have undergone lithium plating and triggers a warning signal, while advising the user to take appropriate measures, such as stopping charging or replacing the battery. If the current characteristic parameter value does not meet the lithium plating threshold condition, it confirms that lithium-ion batteries have not undergone lithium plating.

[0098] In one embodiment, step S202 above involves constructing a lithium-ion battery electrochemical model based on electrochemical parameters, specifically including the following steps:

[0099] Under the premise that the lithium-ion battery meets the preset assumptions, lithium plating kinetic parameters are added to the negative electrode of the lithium-ion battery according to the electrochemical parameters; based on the lithium plating kinetic parameters, charge conservation sub-model, mass conservation sub-model and electrode kinetic sub-model of the lithium-ion battery are constructed as the lithium plating electrochemical model.

[0100] Specifically, the terminal can make the following assumptions about the lithium-ion battery, including: assuming that the active particles in the positive and negative electrodes are uniformly arranged and of the same size; assuming that the charging and discharging process of the lithium-ion battery only occurs in the solid and liquid phases and no gas is generated; assuming that the volume of the lithium-ion battery does not change and the electrode porosity does not change during operation.

[0101] The "Lithium-ion Battery" interface in simulation software such as COMSOL can be used to add lithium plating kinetic parameters to the negative electrode of a lithium-ion battery, including the lithium plating reaction rate constant and the calculation formula for the lithium plating current density. This is based on the lengths of the positive current collector, positive electrode, separator, negative electrode, and negative current collector in a two-dimensional plane, as well as the concentration, volume fraction, diffusion coefficient, conductivity, porous electrode particle radius, and lithium-ion concentration of the battery electrode materials and electrolyte. An electrochemical model of a lithium-ion battery considering lithium plating and the double-layer effect is constructed based on an extension of the pseudo-two-dimensional model (P2D model), including a charge conservation sub-model, a mass conservation sub-model, and an electrode kinetics sub-model.

[0102] The steps for constructing the charge conservation sub-model are as follows: The double-layer capacitance exists at the interface between the positive and negative electrode active material particles and the electrolyte. Due to the extremely small distance between these double layers, a small potential difference can induce a large electric field, which will inevitably affect the Li... + The transfer rate is affected, allowing the pulsed current to pass smoothly. Considering the double-layer effect, the solid-state charge conservation equation is:

[0103]

[0104] In the above formula, Ф s For solid-state potential, i s For solid-state current density, ε is the solid-state conductivity. s γ represents the volume fraction of the solid phase, and γ refers to the Brug coefficient.

[0105] According to the concentrated solution theorem, the conservation of charge in the liquid phase of a battery satisfies the following equation:

[0106]

[0107] In the above formula, Φ is the conductivity of liquid lithium-ion batteries. l Let be the liquid phase potential, R be the gas constant, F be the Faraday constant, T be the absolute temperature, f be the ion activity correlation, and t be the liquid phase potential. + c is the ion transport coefficient. l i represents the lithium-ion liquid phase concentration. l This represents the liquid phase current density.

[0108] The steps to construct the mass conservation sub-model are as follows: According to Fick's second law, the diffusion equation of lithium ions in the solid phase is:

[0109]

[0110] In the above formula, c s D represents the lithium-ion solid phase concentration. s Let r be the solid-phase diffusion coefficient of lithium ions, and r be the coordinate of the active material particle radius direction.p Let be the radius of the active material particle, and j be the reaction current density on the particle surface.

[0111] According to Fick's second law, the diffusion equation of lithium ions in the liquid phase is:

[0112]

[0113] In the above formula, D is the effective lithium-ion liquid phase diffusion coefficient. l is the liquid phase diffusion coefficient.

[0114] The steps for constructing the electrode kinetics sub-model are as follows: Since lithium-ion low-temperature charging may involve lithium plating side reactions, the total electrochemical reaction current on the surface of the active material particles is divided into two parts: the normal lithium-ion insertion / extraction current and the deposition current. Both currents are represented by their respective Butler-Volmer equations, as follows:

[0115]

[0116] In the above formula, j1 is the current density of the normal lithium insertion / extraction reaction, j2 is the current density of the lithium plating side reaction, and j 0，1 and j 0，2 These are the corresponding exchange current densities, α and β. a，1 and α a，2 These are the corresponding anode charge transfer coefficients, α c,1 and α c，2 η1 and η2 are the corresponding cathode charge transfer coefficients, respectively, and η1 and η2 are the corresponding overpotentials.

[0117] The exchange current density during lithium-ion insertion / extraction is expressed by the equation:

[0118]

[0119] In the above formula, k1 is the normal lithium insertion / extraction reaction rate constant, and c s,max c is the maximum lithium concentration on the surface of the active electrode. l c represents the lithium-ion concentration of the electrolyte. l,ref This represents the reference concentration of electrolytes on the surface of the active particles.

[0120] The exchange current density of the lithium plating reaction is expressed as:

[0121]

[0122] In the above formula, k2 is the rate constant of the lithium plating reaction.

[0123] The overpotential of a normal lithium insertion / extraction reaction is as follows:

[0124] n1 = Ф s-Ф l -U eq,1

[0125] In the above formula, U eq，1 is the open-circuit voltage of the positive and negative electrode active materials, which is a function of the battery's state of charge (SOC) and temperature.

[0126] The overpotential of the lithium plating side reaction is as follows:

[0127] η2=Ф s -Ф l -U eq,2

[0128] In the above formula, U eq，2 The equilibrium potential for the lithium plating reaction is generally taken as the lithium metal potential of 0V, R. film The total resistance of the particle surface is denoted as .

[0129] In one embodiment, step S202 above involves constructing a lithium-ion battery lithium plating thermal model based on thermal parameters, specifically including the following steps:

[0130] Based on thermal parameters, the heat source terms in the lithium-ion battery are determined; the heat source terms include polarization heat, ohmic heat, and reaction heat; the total heat generated by the lithium-ion battery is obtained based on the sum of the heat generated by the heat source terms; the total flow heat transfer between the surface of the lithium-ion battery and the air is obtained, and a lithium plating heat model is constructed based on the total heat and the total flow heat transfer.

[0131] Specifically, the terminal can use the "solid heat transfer" interface in simulation software such as COMSOL to establish a thermal model of the lithium-ion battery based on the three-dimensional geometric parameters of the battery to be modeled, the specific heat capacity, thermal conductivity and density parameters of each part of the battery.

[0132] The battery energy balance equation is expressed by the following formula:

[0133]

[0134] In the above formula, ρ is the battery density, and c p Let λ be the specific heat capacity of the battery, λ be the thermal conductivity, and q be the total heat generation rate.

[0135] The energy balance in a lithium-ion battery consists of three heat sources, two of which are irreversible heat sources, namely polarization heat q. act and Ohm's heat Q ohm A reversible heat source is the heat of reaction q. rea The total heat generated by the battery is the sum of the heat generated by the three heat sources.

[0136]

[0137] q act =Sajη

[0138]

[0139] In the above formula, S a It is the specific surface area of ​​the porous electrode. It is the temperature derivative of the equilibrium potential.

[0140] When lithium plating occurs in a battery, the exothermic formula is expressed as:

[0141] q Li =i Li *η2

[0142] In the above formula, q Li This represents the thermal power of the lithium plating reaction.

[0143] The operating temperature of a battery is not only related to the heat generated but also affected by the external environment. Considering only the heat convection between the battery surface and the air in the application scenario of this application, it can be expressed using Newton's law as follows:

[0144] Q = h S (TT amb )

[0145] In the above formula, Q is the total convective heat transfer, h is the convective heat transfer coefficient of the battery surface, S is the convective heat transfer area, and T is the total convective heat transfer area. amb The ambient temperature.

[0146] In one embodiment, as shown in Figure 4, a lithium plating detection method for a lithium-ion battery is provided, which specifically includes the following steps:

[0147] Step S401: Determine the lithium-ion battery to be tested and obtain the battery parameters of the lithium-ion battery; the battery parameters include electrochemical parameters, thermal parameters and geometric parameters.

[0148] Step S402: Under the premise that the lithium-ion battery meets the preset assumptions, lithium plating kinetic parameters are added to the negative electrode of the lithium-ion battery according to the electrochemical parameters; based on the lithium plating kinetic parameters, a charge conservation sub-model, a mass conservation sub-model, and an electrode kinetic sub-model of the lithium-ion battery are constructed as the lithium plating electrochemical model.

[0149] Step S403: Determine the heat source items in the lithium-ion battery based on thermal parameters; the heat source items include polarization heat, ohmic heat and reaction heat; obtain the total heat generated by the lithium-ion battery based on the sum of the heat generated by the heat source items; obtain the total flow heat transfer between the surface of the lithium-ion battery and the air, and construct a lithium plating heat model based on the total heat and the total flow heat transfer.

[0150] Step S404: Construct a lithium plating strain model for lithium-ion batteries based on geometric parameters.

[0151] Step S405: Calculate the heat generation rate of the lithium-ion battery using the lithium plating electrochemical model; obtain the heat generation rate plane based on the heat generation rate; use the heat generation rate plane as the heat source term of the lithium plating thermal model to calculate the temperature of the internal temperature field in the lithium-ion battery; obtain the temperature distribution plane based on the temperature; use the temperature distribution plane as the temperature term of the lithium plating electrochemical model.

[0152] Step S406: Calculate the lithium ion concentration of the lithium plating side reaction in the lithium-ion battery using the lithium plating electrochemical model. Based on the lithium ion concentration, obtain the lithium ion concentration distribution plane. Use the lithium ion concentration distribution plane as the input term of the lithium plating strain model to obtain the electrochemical-thermal-stress coupling model of the lithium-ion battery.

[0153] Step S407: Obtain the temperature and strain data of the lithium-ion battery collected by the fiber Bragg grating device, input the temperature and strain data into the electrochemical-thermal-stress coupling model for numerical calculation and data fitting, and obtain the current characteristic parameter values ​​output by the electrochemical-thermal-stress coupling model.

[0154] Step S408: Determine whether the current characteristic parameter value meets the lithium plating threshold condition; if the current characteristic parameter value meets the lithium plating threshold condition, it is confirmed that lithium plating has occurred in the lithium-ion battery and an early warning signal is triggered; if the current characteristic parameter value does not meet the lithium plating threshold condition, it is confirmed that lithium plating has not occurred in the lithium-ion battery.

[0155] The beneficial effects of the above embodiments are as follows:

[0156] 1) By constructing a multi-physics coupling model (electrochemical-thermal-stress coupling model), the electrochemical behavior, thermal effect and strain effect of the battery are unified in a mathematical model, which improves the accuracy of lithium plating prediction.

[0157] 2) Multiphysics coupling models can derive internal, unmeasurable lithium plating behavior (such as lithium plating rate, amount of lithium plating, and lithium plating location) from externally measurable parameters (temperature, strain) without damaging the battery structure.

[0158] 3) This solution can monitor lithium plating behavior in real time during battery operation and achieve dynamic early warning.

[0159] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0160] Based on the same inventive concept, this application also provides a lithium-ion battery lithium plating detection device for implementing the lithium plating detection method for lithium-ion batteries described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations of one or more lithium-ion battery lithium plating detection device embodiments provided below can be found in the limitations of the lithium plating detection method for lithium-ion batteries described above, and will not be repeated here.

[0161] In an exemplary embodiment, as shown in FIG5, a lithium plating detection device for lithium-ion batteries is provided, comprising:

[0162] The parameter acquisition module 501 is used to identify the lithium-ion battery to be tested and acquire the battery parameters of the lithium-ion battery; the battery parameters include electrochemical parameters, thermal parameters and geometric parameters;

[0163] The model building module 502 is used to build an electrochemical model of lithium-ion battery based on electrochemical parameters, a thermal model of lithium-ion battery based on thermal parameters, and a strain model of lithium-ion battery based on geometric parameters.

[0164] The model coupling module 503 is used to couple the lithium plating electrochemical model with the lithium plating thermal model, and to couple the lithium plating electrochemical model with the lithium plating strain model to obtain the electrochemical-thermal-stress coupling model of the lithium-ion battery.

[0165] The lithium plating simulation module 504 is used to simulate the lithium plating phenomenon of lithium-ion batteries using a lithium plating simulation system, so as to obtain the target characteristic parameter values ​​of lithium-ion batteries when lithium plating occurs, and set the lithium plating threshold conditions based on the target characteristic parameter values.

[0166] The lithium plating detection module 505 is used to obtain the current characteristic parameter values ​​of the lithium-ion battery using an electrochemical-thermal-stress coupling model, and to detect whether lithium plating has occurred in the lithium-ion battery based on the current characteristic parameter values ​​and the lithium plating threshold conditions.

[0167] In one embodiment, the model coupling module 503 is further configured to calculate the heat generation rate of the lithium-ion battery using the lithium plating electrochemical model, obtain a heat generation rate plane based on the heat generation rate, use the heat generation rate plane as the heat source term of the lithium plating thermal model, calculate the temperature of the internal temperature field in the lithium-ion battery, obtain a temperature distribution plane based on the temperature, use the temperature distribution plane as the temperature term of the lithium plating electrochemical model, calculate the lithium ion concentration of the lithium plating side reaction in the lithium-ion battery using the lithium plating electrochemical model, obtain a lithium ion concentration distribution plane based on the lithium ion concentration, and use the lithium ion concentration distribution plane as the input term of the lithium plating strain model.

[0168] In one embodiment, the lithium plating detection device for lithium-ion batteries further includes a data acquisition device for acquiring temperature and strain data of the lithium-ion battery obtained by the fiber Bragg grating device; the lithium plating detection module 505 is also used to input the temperature and strain data into the electrochemical-thermal-stress coupling model for numerical calculation and data fitting to obtain the current characteristic parameter values ​​output by the electrochemical-thermal-stress coupling model.

[0169] In one embodiment, the lithium plating detection module 505 is further configured to determine whether the current characteristic parameter value meets the lithium plating threshold condition; if the current characteristic parameter value meets the lithium plating threshold condition, it is confirmed that lithium plating has occurred in the lithium-ion battery and an early warning signal is triggered; if the current characteristic parameter value does not meet the lithium plating threshold condition, it is confirmed that lithium plating has not occurred in the lithium-ion battery.

[0170] In one embodiment, the model building module 502 is further configured to, under the condition that the lithium-ion battery meets the preset assumptions, add lithium plating kinetic parameters to the negative electrode of the lithium-ion battery according to the electrochemical parameters; and construct a charge conservation sub-model, a mass conservation sub-model, and an electrode kinetic sub-model of the lithium-ion battery according to the lithium plating kinetic parameters, as a lithium plating electrochemical model.

[0171] In one embodiment, the model building module 502 is further configured to determine the heat source terms in the lithium-ion battery based on thermal parameters; the heat source terms include polarization heat, ohmic heat and reaction heat; obtain the total heat generated by the lithium-ion battery based on the sum of the heat generated by the heat source terms; obtain the total flow heat transfer between the surface of the lithium-ion battery and the air; and construct a lithium plating heat model based on the total heat and the total flow heat transfer.

[0172] Each module in the aforementioned lithium-ion battery lithium plating detection device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the corresponding operations of each module.

[0173] In an exemplary embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram is shown in Figure 6. The computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor of the computer device provides computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The input / output interface of the computer device is used for exchanging information between the processor and external devices. The communication interface of the computer device is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, Near Field Communication (NFC), or other technologies. When the computer program is executed by the processor, it implements a lithium plating detection method for lithium-ion batteries. The display unit of the computer device is used to form a visually visible image and may be a display screen, a projection device, or a virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0174] Those skilled in the art will understand that the structure shown in Figure 6 is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or may combine certain components, or may have different component arrangements.

[0175] In one embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0176] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0177] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0178] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0179] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0180] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0181] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A lithium extraction detection method of a lithium ion battery, characterized by, The method includes: Identify the lithium-ion battery to be tested and obtain its battery parameters; the battery parameters include electrochemical parameters, thermal parameters, and geometric parameters. Based on the electrochemical parameters, a lithium plating electrochemical model of the lithium-ion battery is constructed; based on the thermal parameters, a lithium plating thermal model of the lithium-ion battery is constructed; and based on the geometric parameters, a lithium plating strain model of the lithium-ion battery is constructed. The lithium plating electrochemical model is coupled with the lithium plating thermal model, and the lithium plating electrochemical model is coupled with the lithium plating strain model to obtain the electrochemical-thermal-stress coupled model of the lithium-ion battery. The lithium plating phenomenon of the lithium-ion battery is simulated using a lithium plating simulation system to obtain the target characteristic parameter value of the lithium-ion battery when the lithium plating phenomenon occurs, and the lithium plating threshold condition is set according to the target characteristic parameter value. The current characteristic parameter values ​​of the lithium-ion battery are obtained using the electrochemical-thermal-stress coupling model. Based on the current characteristic parameter values ​​and the lithium plating threshold condition, it is detected whether the lithium-ion battery has undergone lithium plating.

2. The method according to claim 1, characterized in that, The coupling of the lithium plating electrochemical model with the lithium plating thermal model, and the coupling of the lithium plating electrochemical model with the lithium plating strain model, includes: The heat generation rate of the lithium-ion battery is calculated using the lithium plating electrochemical model. Based on the heat generation rate, a heat generation rate plane is obtained. The heat generation rate plane is used as the heat source term of the lithium plating thermal model to calculate the temperature of the internal temperature field of the lithium-ion battery. Based on the temperature, a temperature distribution plane is obtained, and the temperature distribution plane is used as the temperature term of the lithium plating electrochemical model. The lithium ion concentration of the lithium-ion battery side reaction is calculated using the lithium-ion electrochemical model. Based on the lithium ion concentration, a lithium ion concentration distribution plane is obtained, and the lithium ion concentration distribution plane is used as the input of the lithium-ion strain model.

3. The method according to claim 1, characterized in that, Before obtaining the current characteristic parameter values ​​of the lithium-ion battery using the electrochemical-thermal-stress coupling model, the method further includes: Acquire temperature and strain data of the lithium-ion battery obtained by fiber Bragg grating equipment; The process of obtaining the current characteristic parameter values ​​of the lithium-ion battery using the electrochemical-thermal-stress coupling model includes: The temperature data and strain data are input into the electrochemical-thermal-stress coupling model for numerical calculation and data fitting to obtain the current characteristic parameter values ​​output by the electrochemical-thermal-stress coupling model.

4. The method according to claim 3, characterized in that, The step of detecting whether the lithium-ion battery has undergone lithium plating based on the current characteristic parameter value and the lithium plating threshold condition includes: Determine whether the current feature parameter value satisfies the lithium plating threshold condition; If the current characteristic parameter value meets the lithium plating threshold condition, it is confirmed that the lithium-ion battery has undergone lithium plating, and a warning signal is triggered. If the current characteristic parameter value does not meet the lithium plating threshold condition, it is confirmed that the lithium-ion battery has not experienced the lithium plating phenomenon.

5. The method according to claim 1, characterized in that, The step of constructing a lithium-ion battery electrochemical model based on the electrochemical parameters includes: Under the premise that the lithium-ion battery meets the preset assumptions, lithium plating kinetic parameters are added to the negative electrode of the lithium-ion battery according to the electrochemical parameters. Based on the lithium plating kinetic parameters, a charge conservation sub-model, a mass conservation sub-model, and an electrode kinetic sub-model of the lithium-ion battery are constructed as the lithium plating electrochemical model.

6. The method according to any one of claims 1 to 5, characterized in that, The step of constructing a lithium-ion battery thermal model based on the thermal parameters includes: Based on the aforementioned thermal parameters, the heat source items in the lithium-ion battery are determined; the heat source items include polarization heat, ohmic heat, and reaction heat. The total heat generated by the lithium-ion battery is obtained based on the sum of the heat generated by the heat sources. Obtain the total heat transfer between the surface of the lithium-ion battery and the air, and construct the lithium plating thermal model based on the total heat and the total heat transfer.

7. A lithium-ion battery lithium plating detection device, characterized in that, The device includes: The parameter acquisition module is used to identify the lithium-ion battery to be tested and acquire the battery parameters of the lithium-ion battery; the battery parameters include electrochemical parameters, thermal parameters and geometric parameters; The model building module is used to build a lithium plating electrochemical model of the lithium-ion battery based on the electrochemical parameters, a lithium plating thermal model of the lithium-ion battery based on the thermal parameters, and a lithium plating strain model of the lithium-ion battery based on the geometric parameters. The model coupling module is used to couple the lithium plating electrochemical model with the lithium plating thermal model, and to couple the lithium plating electrochemical model with the lithium plating strain model, to obtain the electrochemical-thermal-stress coupling model of the lithium-ion battery; The lithium plating simulation module is used to simulate the lithium plating phenomenon of the lithium-ion battery using a lithium plating simulation system, so as to obtain the target characteristic parameter value of the lithium-ion battery when the lithium plating phenomenon occurs, and set the lithium plating threshold condition according to the target characteristic parameter value. The lithium plating detection module is used to obtain the current characteristic parameter values ​​of the lithium-ion battery using the electrochemical-thermal-stress coupling model, and to detect whether the lithium-ion battery has undergone lithium plating based on the current characteristic parameter values ​​and the lithium plating threshold condition.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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