Temperature and heat prediction method, system and equipment for liquid metal battery under external short circuit conditions

Abstract

The present invention discloses a method, system, and device for predicting the temperature and heat of a liquid metal battery under an external short-circuit condition. The method comprises: establishing an external short-circuit model, a thermal model, and a phase change model based on the battery parameters of the liquid metal battery; coupling the three models to obtain a coupled model; in the coupled model, the electrochemical parameters under the external short-circuit condition output by the external short-circuit model are input into the thermal model to calculate the heat source; the temperature output by the thermal model is used to calculate the relevant phase change heat of the phase change model, and the phase change heat output by the phase change model is used as part of the battery heat generation rate in the thermal model; and using the coupled model to calculate the temperature and heat generation rate of the liquid metal battery at different times after the external short circuit occurs, obtaining a temperature and heat generation prediction result for the liquid metal battery under the external short-circuit condition. The present invention can fully consider the factors that affect the temperature and heat generation inside the liquid metal battery under the external short-circuit condition, thereby improving the accuracy of temperature and heat generation prediction under the external short-circuit condition of the liquid metal battery.

Description

Technical Field

[0001] The present invention belongs to the field of liquid metal batteries, and more specifically, relates to a method, system and device for predicting temperature and heat of liquid metal batteries under external short-circuit conditions. Background Art

[0002] The liquid metal battery (LMB) was proposed in 2006 as a new form of energy storage, an all-liquid energy storage battery. It uses liquid metal and molten inorganic salts as electrodes and electrolytes. The electrodes and electrolytes are immiscible and self-isolated, resulting in a simple structure that does not require a special separator design. Compared with traditional secondary battery separators, this battery has lower manufacturing costs and better safety performance. With its low cost, long life, high safety, scalability, and high-rate energy storage, the LMB is a prime candidate for grid-scale energy storage (0.1-1.0GWh), and has broad application prospects in the field of large-scale energy storage.

[0003] Due to the high operating temperatures (300-700°C) and high discharge currents (4-50A) of liquid metal batteries, once an external short circuit occurs, LMBs will result in higher currents and more rapid temperature rises than lithium-ion batteries. While a short-term high current and temperature rise may not immediately damage the battery, they can cause some permanent damage. Therefore, it is necessary to understand the internal temperature distribution and heat generation of liquid metal batteries during external short circuits in order to implement insulation and fire protection measures within the energy storage system.

[0004] Traditional liquid metal battery short-circuit experiments are inherently dangerous, and based on experimental methods to measure battery temperature distribution, the internal phase change heat of the battery will bring a lot of experimental testing work and complex operating procedures, and it does not help experimenters to gain a deep understanding of the battery's internal electrochemical reactions, heat generation, and short-circuit mechanisms. To address this problem, some researchers have proposed establishing an external short-circuit model and a thermal model for liquid metal batteries and coupling the two to predict the temperature and heat of liquid metal batteries under short-circuit conditions.

[0005] When establishing the model, the above method ignores the phase change heat inside the liquid metal battery. However, the high operating temperature and drastic temperature rise under the external short circuit of the liquid metal battery cause the electrode and electrolyte materials to reach the phase change temperature range. Due to the absorption or release of latent heat, the equivalent specific heat capacity of the battery electrode electrolyte material usually increases significantly, making the phase change heat inside the liquid metal battery no longer negligible. Therefore, the modeling process of the above modeling method does not fully consider the factors affecting the temperature and heat inside the liquid metal battery under external short circuit conditions, and the accuracy of the prediction results needs to be further improved. Summary of the Invention

[0006] In response to the defects of the existing technology and the need for improvement, the present invention provides a method, system and equipment for predicting the temperature and heat of a liquid metal battery under external short-circuit conditions. The purpose is to fully consider the factors affecting the temperature and heat inside the liquid metal battery under external short-circuit conditions, and to improve the accuracy of temperature and heat prediction under external short-circuit conditions of the liquid metal battery.

[0007] To achieve the above objectives, according to one aspect of the present invention, a method for predicting temperature and heat of a liquid metal battery under external short-circuit conditions is provided, comprising:

[0008] According to the battery parameters of the liquid metal battery, an external short-circuit model, a thermal model and a phase change model are established respectively; the battery parameters include geometric parameters, electrochemical parameters, thermodynamic parameters and phase change material parameters; the external short-circuit model is used to describe the external short-circuit working condition and the electrochemical mechanism of the liquid metal battery under the external short-circuit working condition; the thermal model is used to describe the thermal law in the furnace cavity where the liquid metal battery is located; the phase change model is used to describe the phase change heat absorbed or released by the electrodes and electrolyte materials in the liquid metal battery when they transform from solid to liquid;

[0009] The external short-circuit model, thermal model, and phase change model are coupled to obtain a coupled model. In the coupled model, the electrochemical parameters under the external short-circuit condition output by the external short-circuit model are input into the thermal model to calculate the heat source. The temperature output by the thermal model is used to calculate the relevant phase change heat of the phase change model as the heat source of the phase change model. The phase change heat output by the phase change model is used as part of the battery heat generation rate in the thermal model.

[0010] The coupling model is used to calculate the temperature and heat generation rate of the liquid metal battery at different times after an external short circuit occurs, and the temperature and heat generation rate prediction results of the liquid metal battery under external short circuit conditions are obtained.

[0011] Furthermore, the external short-circuit model is:

[0012]

[0013] in, is the Laplace operator; t is time; c1 is the positive electrode lithium concentration, c2 is the electrolyte lithium ion concentration; D1 is the positive electrode lithium concentration diffusion rate, D2 is the electrolyte lithium ion concentration; v is the chemical reaction rate, F is the Faraday constant, n is the number of electrons involved in the reaction; j loc represents the local current density; z2 represents the valence of lithium ions, u2 represents the velocity of the fluid, represents the electrolyte potential; η represents the activation overpotential, represents the electrode potential, represents the electrolyte potential, E eq represents the equilibrium potential; φ1| xrepresents the potential at position x; boudary1, boudary2, boudary3, and boudary4 represent the negative electrode external interface, the interface between the negative electrode and the electrolyte, the interface between the positive electrode and the electrolyte, and the positive electrode external interface, respectively; A represents the cross-sectional area of ​​the battery, I cell represents the battery current, σ1 represents the conductivity of the electrode; I ESC Indicates external short-circuit current, R ESC Indicates external short-circuit resistance.

[0014] Furthermore, the thermal model is:

[0015]

[0016] q cell =q act +q ohm +q rea +Q 相变

[0017] q act =S a,i j loc η

[0018]

[0019]

[0020] Where ρ represents the average density of the phase change material, C p represents constant pressure hot melt, T represents battery temperature, k represents the average thermal conductivity of phase change material; q cell represents the heat generation rate of the electrochemical reaction, q dissipation Indicates the heat dissipation between the battery and the outside world, q heater Indicates the heating furnace power; q act represents the activation heat, q ohm represents ohmic heat, q rea represents the heat of reaction, Q 相变 represents phase change heat; S a,i represents the interface area between the electrode and the electrolyte; i1 represents the positive electrode current, i 1′ represents the negative electrode current, i2 represents the electrolyte current, represents the positive electrode potential, φ 1′ Indicates the negative electrode potential; U OCV represents the open circuit voltage; j represents the convection heat transfer coefficient, T amb represents the ambient temperature, ε represents the emissivity, σ B represents the Stefan-Boltzmann constant.

[0021] Furthermore, the phase change model is:

[0022]

[0023] ρ=θ1ρ1+θ2ρ2

[0024]

[0025] k=θ1k1+θ2k2

[0026] θ1+θ2=1

[0027] Among them, T start Indicates the starting temperature of material phase change, T end Indicates the temperature at which the material phase change ends; c p (T) represents the effective specific heat capacity of the phase change material when the battery temperature is T; θ1 and θ2 represent the mass fractions of solid and liquid phase change materials, respectively; ρ1 and ρ2 represent the densities of solid and liquid phase change materials, respectively; c p,1 and c p,2 represent the specific heat capacity of solid and liquid phase change materials respectively; c p,2 represents the latent heat of phase change; α m represents the average thermal expansion coefficient of the phase change material; k r and k2 represent the thermal conductivity of solid and liquid phase change materials, respectively, and k represents the average thermal conductivity of the phase change material.

[0028] According to another aspect of the present invention, a temperature and heat prediction system for a liquid metal battery under external short-circuit conditions is provided, comprising:

[0029] The initialization module is used to establish an external short-circuit model, a thermal model, and a phase change model based on the battery parameters of the liquid metal battery. The battery parameters include geometric parameters, electrochemical parameters, thermodynamic parameters, and phase change material parameters. The external short-circuit model is used to describe the external short-circuit working condition and the electrochemical mechanism of the liquid metal battery under the external short-circuit working condition. The thermal model is used to describe the thermal law in the furnace cavity where the liquid metal battery is located. The phase change model is used to describe the phase change heat absorbed or released by the electrodes and electrolyte materials in the liquid metal battery during the solid-liquid phase transition.

[0030] A coupling module is used to couple the external short-circuit model, the thermal model, and the phase change model to obtain a coupled model. In the coupled model, the electrochemical parameters under the external short-circuit condition output by the external short-circuit model are input into the thermal model to calculate the heat source. The temperature output by the thermal model is used to calculate the relevant phase change heat of the phase change model as the heat source of the phase change model. The phase change heat output by the phase change model is used as part of the battery heat generation rate in the thermal model.

[0031] And a prediction module, which is used to use a coupling model to calculate the temperature and heat generation rate of the liquid metal battery at different times after an external short circuit occurs, and obtain the temperature and heat prediction results of the liquid metal battery under external short circuit conditions.

[0032] According to another aspect of the present invention, a computer program product is provided, comprising a computer program; when the computer program is executed by a processor, the temperature and heat prediction method under any one of the above-mentioned liquid metal battery external short-circuit conditions provided by the present invention is implemented.

[0033] According to another aspect of the present invention, a computer-readable storage medium is provided, comprising a stored computer program; when the computer program is executed by a processor, the device where the computer-readable storage medium is located is controlled to execute any of the above-mentioned temperature and heat prediction methods for liquid metal batteries under external short-circuit conditions provided by the present invention.

[0034] According to another aspect of the present invention, there is provided a device for predicting temperature and heat of a liquid metal battery under external short-circuit conditions, comprising:

[0035] a computer-readable storage medium for storing a computer program;

[0036] and a processor for reading a computer program stored in a computer-readable storage medium to implement any of the temperature and heat prediction methods for a liquid metal battery under an external short-circuit condition provided by the present invention.

[0037] In general, through the above technical solutions conceived by the present invention, a corresponding external short-circuit model, thermal model and phase change model are established based on the electrochemical mechanism and thermal laws inside the battery, and the three are coupled together to establish a coupling model for predicting the dynamic temperature response of the battery under external short-circuit conditions. Based on this coupling model, it is possible to perform destructive and dangerous short-circuit experiments without conducting destructive and dangerous short-circuit experiments. In addition, based on the non-negligible characteristics of the phase change heat generated by phase change materials such as motors and electrolytes due to high operating temperatures and drastic temperature rises under external short-circuit conditions, a phase change model is established, and the phase change heat calculated based on the phase change model is used as part of the heat generation rate of the battery electrochemical reaction in the thermal model. The coupling model finally established is more consistent with the electrochemical mechanism and thermal laws of the liquid metal battery under external short-circuit conditions, effectively improving the prediction accuracy of temperature and heat, and providing a more reliable reference basis for the design of high-safety liquid metal battery cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic diagram of the two-dimensional geometric structure of the Li||LiF-LiCl-LiBr||Bi system liquid metal battery;

[0039] Figure 2 A flow chart of a method for predicting temperature and heat of a liquid metal battery under external short-circuit conditions provided by an embodiment of the present invention;

[0040] Figure 3 A one-dimensional electrochemical geometric structure provided by an embodiment of the present invention;

[0041] Figure 4 Temperature distribution cloud maps of the liquid metal battery provided by the embodiment of the present invention under different external short-circuit conditions; wherein (a) is the temperature distribution cloud map of the liquid metal battery at the start of the external short circuit under the external short-circuit condition of 50% SOC and access to a 0.5mΩ external short-circuit resistor; (b) is the temperature distribution cloud map of the liquid metal battery 20 seconds after the external short circuit occurs under the external short-circuit condition of 50% SOC and access to a 0.5mΩ external short-circuit resistor;

[0042] Figure 5 The temperature change curve of the battery outer surface during the external short-circuit process when the liquid metal battery provided by the embodiment of the present invention is at 50% SOC and connected to different external short-circuit resistors. DETAILED DESCRIPTION

[0043] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0044] In the present invention, the terms "first", "second", etc. (if any) in the present invention and the drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0045] In order to more accurately predict the temperature and heat of a liquid metal battery under an external short-circuit condition without destroying the external structure of the battery or damaging the battery, and to provide a reference for designing high-safety liquid metal batteries, the present invention provides a method, system and device for predicting the temperature and heat of a liquid metal battery under an external short-circuit condition. The overall concept is to fully consider the electrochemical mechanism inside the liquid metal battery under the external short-circuit condition and the influence of the phase change heat generated by the dielectric and electrode materials on the battery temperature and heat, establish an external short-circuit model, a thermal model and a phase change model of the liquid metal battery respectively, and use the phase change heat as part of the heat generation rate of the battery electrochemical reaction in the thermal model, so that the coupled model obtained by coupling the three models can accurately characterize the external short-circuit condition of the liquid metal battery, thereby improving the prediction accuracy of the temperature and heat under the external short-circuit condition.

[0046] Liquid metal batteries differ from conventional lithium batteries in that they consist of five parts: anode current collector, cathode material, electrolyte molten salt, cathode material, and cathode current collector. Without loss of generality, the following examples all take the Li||LiF-LiCl-LiBr||Bi system liquid metal battery as an example, and its geometric structure is as follows: Figure 1 shown. Figure 1In the figure, “Lithium[liquid]” represents the positive electrode current collector, “Bismuth” represents the negative electrode current collector, “LiF:LiCI:LiBr” represents the positive electrode material, electrolyte lava and negative electrode material, “Air” represents the gas in the furnace chamber, and the outside represents the insulation layer.

[0047] The following are examples.

[0048] Example 1:

[0049] A method for predicting temperature and heat of a liquid metal battery under external short circuit conditions, such as Figure 2 Shown, including:

[0050] According to the battery parameters of the liquid metal battery, an external short circuit model, a thermal model and a phase change model are established respectively; the battery parameters include geometric parameters, electrochemical parameters, thermodynamic parameters and phase change material parameters; the geometric parameters include at least one of the following: the thickness of the metal layer of the positive and negative electrodes of the battery, the distance between the positive and negative electrodes, and the height of the positive and negative current collectors; the electrochemical parameters include at least one of the following: reaction activation energy, reaction molar enthalpy change, and maximum lithium concentration of the negative electrode; the thermodynamic parameters include at least one of the following: the specific heat capacity, density, thermal conductivity, and emissivity of the battery; the phase change parameters include at least one of the following: the latent heat of phase change of the material, the solid-liquid specific heat capacity of the material, and the phase change temperature range; the external short circuit model is used to describe the external short circuit working condition and the electrochemical mechanism of the liquid metal battery under the external short circuit working condition; the thermal model is used to describe the thermal law in the furnace cavity where the liquid metal battery is located; the phase change model is used to describe the phase change heat absorbed or released by the electrodes and electrolyte materials in the liquid metal battery when they transform from solid to liquid;

[0051] The external short-circuit model, thermal model, and phase change model are coupled to obtain a coupled model. In the coupled model, the electrochemical parameters under the external short-circuit condition output by the external short-circuit model are input into the thermal model to calculate the heat source. The temperature output by the thermal model is used to calculate the relevant phase change heat of the phase change model as the heat source of the phase change model. The phase change heat output by the phase change model is used as part of the battery heat generation rate in the thermal model.

[0052] The coupling model is used to calculate the temperature and heat generation rate of the liquid metal battery at different times after an external short circuit occurs, and the temperature and heat generation rate prediction results of the liquid metal battery under external short circuit conditions are obtained.

[0053] In this embodiment, the establishment of the electrochemical model specifically includes: constructing a geometric model of the basic unit of the battery based on the size of the battery; then setting each working domain in the model, and filling the electrochemical parameters into the corresponding model.

[0054] In this embodiment, the positive and negative electrodes and the length of the electrolyte corresponding to the actual object are set according to the size parameters of the liquid metal battery to form a one-dimensional electrochemical geometric structure of the model, such as Figure 3As shown in the figure, "Anode" represents the positive electrode, "Electrolyte" represents the electrolyte, "cathode" represents the negative electrode, and boudary1, boudary2, boudary3, and boudary4 represent the negative electrode external interface, the interface between the negative electrode and the electrolyte, the interface between the positive electrode and the electrolyte, and the positive electrode external interface, respectively. Finally, the established external short-circuit model includes:

[0055]

[0056] in, is the Laplace operator; t is time; c1 is the positive electrode lithium concentration, c2 is the electrolyte lithium ion concentration; D1 is the positive electrode lithium concentration diffusion rate, D2 is the electrolyte lithium ion concentration; ν is the chemical reaction rate, F is the Faraday constant, and n is the number of electrons involved in the reaction; j loc represents the local current density; z2 represents the valence of lithium ions, u2 represents the velocity of the fluid, represents the electrolyte potential; η represents the activation overpotential, represents the electrode potential, represents the electrolyte potential, E eq represents the equilibrium potential; φ1| x represents the potential at position x; boudary1, boudary2, boudary3, and boudary4 represent the negative electrode external interface, the interface between the negative electrode and the electrolyte, the interface between the positive electrode and the electrolyte, and the positive electrode external interface, respectively; A represents the cross-sectional area of ​​the battery, I cell represents the battery current, σ1 represents the conductivity of the electrode; I ESC Indicates external short-circuit current, R ESC Indicates external short-circuit resistance.

[0057] The scope of the external short-circuit model is the electrode and electrolyte, where formula (1) is the mass balance equation of the positive electrode lithium concentration, formula (2) is the mass balance equation of the electrolyte ions, formula (3) is the potential equation of the electrode-electrolyte cross section, formula (4) is the boundary condition, formula (5) is the external current equation, and formula (6) is the external short-circuit condition.

[0058] In this embodiment, the establishment of the thermal model specifically includes: constructing a geometric model of the battery cell based on the size of the battery; then setting the materials and ambient temperature of each battery component, and filling the thermal parameters of the battery into the corresponding area; the temperature field change of the battery follows Fourier's law.

[0059] Finally, the thermal model established in this embodiment is:

[0060]

[0061] qcell =q irrev +q rev =q act +q ohm +q rea +Q 相变 (8)

[0062] q act =S a,i j loc η (9)

[0063]

[0064] Where ρ represents the average density of the phase change material, C p represents constant pressure hot melt, T represents battery temperature, k represents the average thermal conductivity of phase change material; q cell represents the heat generation rate of the electrochemical reaction, represents the reversible heat, q rev represents irreversible heat; q dissipation Indicates the heat dissipation between the battery and the outside world, q heater Indicates the heating furnace power; q act represents the activation heat, q ohm represents ohmic heat, q rea represents the heat of reaction, Q 相变 represents phase change heat; S a,i represents the interface area between the electrode and the electrolyte; i1 represents the positive electrode current, i 1′ represents the negative electrode current, i2 represents the electrolyte current, represents the positive electrode potential, φ 1′ Indicates the negative electrode potential; U OCV represents the open circuit voltage; q conv represents conduction heat, q rad represents radiation heat; h represents the convective heat transfer coefficient, T amb represents the ambient temperature, ε represents the emissivity, σ B represents the Stefan-Boltzmann constant.

[0065] The scope of the thermal model is the entire liquid metal battery, where formula (7) is the energy balance equation, formulas (8) to (11) are the heat dissipation calculation formulas, and formula (12) is the boundary equation that uses natural convection and radiation to describe the heat dissipation behavior between the liquid metal battery and the outside world. In formula (8), the heat generation rate q of the electrochemical reaction is calculated cell In addition to considering the activation heat, ohmic heat and reaction heat, the phase change heat Q under external short circuit conditions which cannot be ignored is also considered. 相变 .

[0066] The scope of the phase change model is the electrode and the electrolyte. The phase change model established in this embodiment is:

[0067]

[0068] ρ=θ1ρ1+θ2ρ2 (14)

[0069]

[0070]

[0071] k=θ1k1+θ2k2 (17)

[0072] θ1+θ2=1 (18)

[0073] Among them, T start Indicates the starting temperature of material phase change, T end Indicates the temperature at which the material phase change ends; c p (T) represents the effective specific heat capacity of the phase change material when the battery temperature is T; θ1 and θ2 represent the mass fractions of solid and liquid phase change materials, respectively; ρ1 and ρ2 represent the densities of solid and liquid phase change materials, respectively; c p,1 and c p,2 represent the specific heat capacity of solid and liquid phase change materials respectively; c p,2 represents the latent heat of phase change; α m represents the average thermal expansion coefficient of the phase change material, represents the rate of change of the average thermal expansion coefficient with temperature; k1 and k2 represent the thermal conductivity of solid and liquid phase change materials respectively, and k represents the average thermal conductivity of the phase change material.

[0074] In practical applications, simulation software such as COMSOL can be used to achieve the coupling of external short-circuit models, thermal models, and phase change models, as well as the prediction of temperature and heat.

[0075] In general, the temperature and heat prediction method for liquid metal batteries under external short-circuit conditions provided in this embodiment can predict battery temperature and heat generation power (heat) through a model without conducting destructive and dangerous short-circuit experiments, and can estimate the heat conditions of battery electrolytes and electrode phase changes, thereby improving the accuracy of temperature and heat prediction, saving battery management costs, and providing a reference for subsequent battery group safety control.

[0076] The temperature and heat prediction method of the liquid metal battery under the external short circuit condition provided in this embodiment is used to predict the temperature of the liquid metal battery under different external short circuit conditions, and draw a temperature distribution cloud map. The results are as follows: Figure 4 As shown, Figure 4 (a) is the temperature distribution cloud diagram of the liquid metal battery at the start of the external short circuit when the external short circuit is connected to a 0.5mΩ external short circuit resistor at 50% SOC. Figure 4(b) is the temperature distribution cloud diagram of the liquid metal battery 20s after the external short circuit occurs under the external short circuit condition of 50% SOC and access to a 0.5mΩ external short circuit resistor; Figure 4 The predicted results are consistent with the measured results under actual external short-circuit experiments.

[0077] This embodiment is further used to predict the temperature change of the battery surface during the external short circuit when the liquid metal battery is at 50% SOC and connected to different external short circuit resistors, and the corresponding curve is drawn, such as Figure 5 As shown, according to Figure 5 As shown in the figure, the smaller the external short-circuit resistance, the greater the temperature rise rate. This simulation result is consistent with the temperature rise trend of the liquid metal battery under the external short-circuit condition.

[0078] Figure 4 and Figure 5 The results show that this embodiment can accurately predict the temperature and heat of the liquid metal battery under external short-circuit conditions.

[0079] Example 2:

[0080] A temperature and heat prediction system for a liquid metal battery under external short-circuit conditions, comprising:

[0081] The initialization module is used to establish an external short-circuit model, a thermal model, and a phase change model based on the battery parameters of the liquid metal battery. The battery parameters include geometric parameters, electrochemical parameters, thermodynamic parameters, and phase change material parameters. The external short-circuit model is used to describe the external short-circuit working condition and the electrochemical mechanism of the liquid metal battery under the external short-circuit working condition. The thermal model is used to describe the thermal law in the furnace cavity where the liquid metal battery is located. The phase change model is used to describe the phase change heat absorbed or released by the electrodes and electrolyte materials in the liquid metal battery during the solid-liquid phase transition.

[0082] A coupling module is used to couple the external short-circuit model, the thermal model, and the phase change model to obtain a coupled model. In the coupled model, the electrochemical parameters under the external short-circuit condition output by the external short-circuit model are input into the thermal model to calculate the heat source. The temperature output by the thermal model is used to calculate the relevant phase change heat of the phase change model as the heat source of the phase change model. The phase change heat output by the phase change model is used as part of the battery heat generation rate in the thermal model.

[0083] And a prediction module, which is used to use a coupling model to calculate the temperature and heat generation rate of the liquid metal battery at different times after an external short circuit occurs, and obtain the temperature and heat prediction results of the liquid metal battery under external short circuit conditions.

[0084] In this embodiment, the specific implementation of each module can refer to the description in the above embodiment 1 and will not be repeated here.

[0085] Example 3:

[0086] A computer program product includes a computer program; when the computer program is executed by a processor, it implements the temperature and heat prediction method under the external short-circuit condition of the liquid metal battery provided in the above embodiment 1.

[0087] Example 4:

[0088] A computer-readable storage medium includes a stored computer program; when the computer program is executed by a processor, the device containing the computer-readable storage medium is controlled to execute the temperature and heat prediction method for a liquid metal battery under an external short-circuit condition provided in the above-mentioned embodiment 1.

[0089] Example 5:

[0090] A temperature and heat prediction device for a liquid metal battery under external short-circuit conditions, comprising:

[0091] a computer-readable storage medium for storing a computer program;

[0092] and a processor for reading a computer program stored in a computer-readable storage medium to implement the temperature and heat prediction method for a liquid metal battery under an external short-circuit condition provided in the above-mentioned embodiment 1.

[0093] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for predicting temperature and heat of a liquid metal battery under external short-circuit conditions, characterized in that: include: An external short-circuit model, a thermal model, and a phase change model are established according to the battery parameters of the liquid metal battery; the battery parameters include geometric parameters, electrochemical parameters, thermodynamic parameters, and phase change material parameters; the external short-circuit model is used to describe the external short-circuit working condition and the electrochemical mechanism of the liquid metal battery under the external short-circuit working condition; the thermal model is used to describe the thermal law in the furnace cavity where the liquid metal battery is located; the phase change model is used to describe the phase change heat absorbed or released by the electrodes and electrolyte materials in the liquid metal battery during the solid-liquid phase transition; The external short-circuit model, the thermal model, and the phase change model are coupled to obtain a coupled model; in the coupled model, the electrochemical parameters under the external short-circuit condition output by the external short-circuit model are input into the thermal model for calculating the heat source, the temperature output by the thermal model is used to calculate the relevant phase change heat of the phase change model as the heat source of the phase change model, and the phase change heat output by the phase change model is used as part of the battery heat generation rate in the thermal model; The coupling model is used to calculate the temperature and heat generation rate of the liquid metal battery at different times after an external short circuit occurs, and the temperature and heat generation rate prediction results of the liquid metal battery under the external short circuit condition are obtained.

2. The temperature and heat prediction method of a liquid metal battery under external short-circuit conditions according to claim 1, characterized in that: The external short-circuit model is: in, is the Laplace operator; t is time; c1 is the positive electrode lithium concentration, c2 is the electrolyte lithium ion concentration; D1 is the positive electrode lithium concentration diffusion rate, D2 is the electrolyte lithium ion concentration; v is the chemical reaction rate, F is the Faraday constant, n is the number of electrons involved in the reaction; j loc represents the local current density; z2 represents the valence of lithium ions, u2 represents the velocity of the fluid, represents the electrolyte potential; η represents the activation overpotential, represents the electrode potential, represents the electrolyte potential, E eq represents the equilibrium potential; φ1| x represents the potential at position x; boudary1, boudary2, boudary3, and boudary4 represent the negative electrode external interface, the interface between the negative electrode and the electrolyte, the interface between the positive electrode and the electrolyte, and the positive electrode external interface, respectively; A represents the cross-sectional area of ​​the battery, I cell represents the battery current, σ1 represents the conductivity of the electrode; I ESC Indicates external short-circuit current, R ESC Indicates external short-circuit resistance.

3. The temperature and heat prediction method of a liquid metal battery under external short-circuit conditions according to claim 2, characterized in that: The thermal model is: q cell =q act +q ohm +q rea +Q 相变 what act =S a,i j loc the Where ρ represents the average density of the phase change material, C p represents constant pressure hot melt, T represents battery temperature, k represents the average thermal conductivity of phase change material; q cell represents the heat generation rate of the electrochemical reaction, q dissipation Indicates the heat dissipation between the battery and the outside world, q heater Indicates the heating furnace power; q act represents the activation heat, q ohm represents ohmic heat, q rea represents the heat of reaction, Q 相变 represents phase change heat; S a,i represents the interface area between the electrode and the electrolyte; i1 represents the positive electrode current, i 1′ represents the negative electrode current, i2 represents the electrolyte current, represents the positive electrode potential, Indicates the negative electrode potential; U OCV represents the open circuit voltage; h represents the convection heat transfer coefficient, T amb represents the ambient temperature, ε represents the emissivity, σ B represents the Stefan-Boltzmann constant.

4. The temperature and heat prediction method of a liquid metal battery under external short-circuit conditions according to claim 3, characterized in that: The phase change model is: ρ=θ1ρ1+θ2ρ2 k=θ1k1+θ2k2 θ1+θ2=1 Among them, T start Indicates the starting temperature of material phase change, T end Indicates the temperature at which the material phase change ends; c p (T) represents the effective specific heat capacity of the phase change material when the battery temperature is T; θ1 and θ2 represent the mass fractions of solid and liquid phase change materials, respectively; ρ1 and ρ2 represent the densities of solid and liquid phase change materials, respectively; c p,1 and c p,2 represent the specific heat capacity of solid and liquid phase change materials respectively; c p,2 represents the latent heat of phase change; α m represents the average thermal expansion coefficient of the phase change material; k1 and k2 represent the thermal conductivity of the solid and liquid phase change materials respectively, and k represents the average thermal conductivity of the phase change material.

5. A temperature and heat prediction system for a liquid metal battery under external short-circuit conditions, characterized in that: include: An initialization module is used to establish an external short-circuit model, a thermal model, and a phase change model according to the battery parameters of the liquid metal battery; the battery parameters include geometric parameters, electrochemical parameters, thermodynamic parameters, and phase change material parameters; the external short-circuit model is used to describe the external short-circuit working condition and the electrochemical mechanism of the liquid metal battery under the external short-circuit working condition; the thermal model is used to describe the thermal law in the furnace cavity where the liquid metal battery is located; the phase change model is used to describe the phase change heat absorbed or released by the electrodes and electrolyte materials in the liquid metal battery during the solid-liquid phase transition; a coupling module, configured to couple the external short-circuit model, the thermal model, and the phase change model to obtain a coupled model; in the coupled model, the electrochemical parameters under the external short-circuit condition output by the external short-circuit model are input into the thermal model for calculating a heat source, the temperature output by the thermal model is used to calculate the relevant phase change heat of the phase change model as the heat source of the phase change model, and the phase change heat output by the phase change model is used as part of the battery heat generation rate in the thermal model; And a prediction module is used to calculate the temperature and heat generation rate of the liquid metal battery at different times after the external short circuit occurs by using the coupling model, and obtain the temperature and heat prediction results of the liquid metal battery under the external short circuit condition.

6. A computer program product, characterized in that The method comprises a computer program; when the computer program is executed by a processor, the method for predicting temperature and heat of a liquid metal battery under an external short-circuit condition according to any one of claims 1 to 4 is implemented.

7. A computer-readable storage medium, characterized in that Including a stored computer program; when the computer program is executed by a processor, it controls the device where the computer-readable storage medium is located to execute the temperature and heat prediction method under the external short-circuit condition of the liquid metal battery according to any one of claims 1 to 4.

8. A temperature and heat prediction device for a liquid metal battery under external short-circuit conditions, characterized in that: include: a computer-readable storage medium for storing a computer program; and a processor for reading the computer program stored in the computer-readable storage medium to implement the temperature and heat prediction method under the external short-circuit condition of the liquid metal battery according to any one of claims 1 to 4.

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