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

Abstract

The invention discloses a temperature and heat prediction method, system and equipment for a liquid metal battery under an external short circuit working condition. The method comprises the following steps: respectively establishing an external short circuit model, a heat model and a phase change model according to battery parameters of the liquid metal battery; coupling the three models to obtain a coupled model; in the coupling model, the electrochemical parameters output by the external short-circuit model under the external short-circuit working condition are input into the thermal model for calculating a heat source, the temperature output by the thermal model is used for calculating the related phase change heat of the phase change model, and the phase change heat output by the phase change model serves as a part of the heat production rate of the battery in the thermal model; and calculating temperatures and heat production rates of the liquid metal battery at different moments by using the coupling model after the external short circuit occurs, and obtaining temperature and heat prediction results of the liquid metal battery under the working condition of the external short circuit. According to the method, factors influencing the temperature and heat in the liquid metal battery under the external short-circuit working condition can be fully considered, and the temperature and heat prediction accuracy of the liquid metal battery under the external short-circuit working condition is improved.

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 a liquid metal battery under external short-circuit conditions. Background Art

[0002] 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 salt as electrodes and electrolytes. The electrodes and electrolytes are immiscible in density and self-isolated, so the structure is simple and does not require special diaphragm design. Compared with traditional secondary battery diaphragms, the battery has lower manufacturing costs and better safety performance. Liquid metal batteries have the characteristics of low cost, long life, high safety scalability and high rate energy storage, making LMB a major candidate for grid-scale energy storage (0.1-1.0GWh), and have broad application prospects in the field of large-scale energy storage.

[0003] The working characteristics of liquid metal batteries, such as high operating temperature (300-700℃) and high discharge current (4-50A), make LMB cause larger current and more rapid temperature rise than lithium-ion batteries once an external short circuit failure of liquid metal batteries occurs. A short-term high current and temperature rise may not destroy the battery immediately, but it will cause certain permanent damage to the battery. Therefore, it is necessary to obtain the temperature distribution and heat inside the battery when the liquid metal battery is short-circuited, so as to set up insulation and fire protection measures inside 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 cannot help experimenters deeply understand the internal electrochemical reactions, heat generation and short-circuit mechanisms of the battery. To address this problem, some researchers proposed to establish an external short-circuit model and a thermal model of the liquid metal battery and couple the two to predict the temperature and heat of the liquid metal battery 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 make the electrode and electrolyte materials 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 is usually significantly increased, 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 view of the defects of the prior art 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 prediction accuracy of the temperature and heat under external short-circuit conditions of the liquid metal battery.

[0007] To achieve the above object, 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, the external short circuit model, thermal model and 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 condition and the electrochemical mechanism of the liquid metal battery under the external short circuit 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 the solid and liquid states are transformed into each other;

[0009] 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 a part of the heat generation rate of the battery 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 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 represents time; c 1 is the positive electrode lithium concentration, c 2 is the lithium ion concentration of the electrolyte; D 1 Denotes the diffusion rate of positive electrode lithium concentration, D 2 represents the lithium ion concentration of the electrolyte; v represents the chemical reaction rate, F represents the Faraday constant, n represents the number of electrons involved in the reaction; j loc represents the local current density; z 2 represents the valence of lithium ions, u 2 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; φ 1 | x represents the potential at position x; baudary1, baudary2, baudary3 and baudary4 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, σ 1 Indicates the conductivity of the electrode; I ESC Represents 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 represents 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 interfacial area between the electrode and the electrolyte; i 1 represents the positive current, i 1′ Represents the negative electrode current, i 2 represents the electrolyte current, represents the positive electrode potential, i 1′ Indicates the negative electrode potential; U OCV represents the open circuit voltage; j represents the convection heat transfer coefficient, T ambrepresents the ambient temperature, ε represents the emissivity, σ B represents the Stefan-Boltzmann constant.

[0021] Furthermore, the phase change model is:

[0022]

[0023] ρ=θ 1 ρ 1 +θ 2 ρ 2

[0024]

[0025] k=θ 1 k 1 +θ 2 k 2

[0026] θ 1 +θ 2 =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; θ 1 and θ 2 Respectively represent the mass fraction of solid and liquid phase change materials; ρ 1 and ρ 2 Represent the density 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 k 2 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 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 condition and the electrochemical mechanism of the liquid metal battery under the external short-circuit 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 the solid-liquid state is transformed into each other;

[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 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 a part of the heat generation rate of the battery in the thermal model;

[0031] And a prediction module is used to calculate the temperature and heat generation rate of the liquid metal battery at different times after an external short circuit occurs by using a coupling model, 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 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 temperature and heat prediction methods under external short-circuit conditions of a liquid metal battery provided by the present invention.

[0034] According to another aspect of the present invention, there is provided a temperature and heat prediction device for 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 scheme 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 in an external short-circuit condition. Based on the 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 a 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 designing 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 diagrams of the liquid metal battery provided in the embodiment of the present invention under different external short-circuit conditions; wherein (a) is a temperature distribution cloud diagram of the liquid metal battery at the start time of the external short circuit under the external short circuit condition of 50% SOC and access to a 0.5mΩ external short-circuit resistor, and (b) is a 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;

[0042] Figure 5 The temperature variation curve of the outer surface of the battery during the external short circuit process when the liquid metal battery provided in 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 purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain 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 can 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 accompanying drawings are used to distinguish similar objects but not necessarily 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 a highly safe liquid metal battery, the present invention provides a temperature and heat prediction method, system and device for 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 the electrode material on the battery temperature and heat, respectively establish an external short-circuit model, a thermal model and a phase change model of the liquid metal battery, and use the phase change heat as a 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 are different from conventional lithium batteries. Liquid metal batteries contain five parts: positive electrode current collector, positive electrode material, electrolyte molten salt, negative electrode material, and negative electrode current collector. Without loss of generality, the following embodiments all take the Li||LiF-LiCl-LiBr||Bi system liquid metal battery as an example. Its geometric structure is as follows Figure 1 shown. Figure 1 In 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] Embodiment 1:

[0049] A method for predicting temperature and heat of a liquid metal battery under external short circuit conditions, such as Figure 2 As 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: the reaction activation energy, the reaction molar enthalpy change, and the 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 the solid and liquid states are transformed into each other;

[0051] 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 a part of the heat generation rate of the battery 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 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, according to the size parameters of the liquid metal battery, the positive and negative electrodes and the electrolyte length corresponding to the actual object are set to form a one-dimensional electrochemical geometric structure of the model, such as Figure 3 As shown in the figure, "Anode" represents the positive electrode, "Electrolyte" represents the electrolyte, "cathode" represents the negative electrode, and baudary1, baudary2, baudary3 and baudary4 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 represents time; c 1 is the positive electrode lithium concentration, c2 is the lithium ion concentration of the electrolyte; D 1 Denotes the diffusion rate of positive electrode lithium concentration, D 2 represents the lithium ion concentration of the electrolyte; ν represents the chemical reaction rate, F represents the Faraday constant, n represents the number of electrons involved in the reaction; j loc represents the local current density; z 2 represents the valence of lithium ions, u 2 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; φ 1 | x represents the potential at position x; baudary1, baudary2, baudary3 and baudary4 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, σ 1 Indicates the conductivity of the electrode; I ESC Represents 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 for the positive electrode lithium concentration, formula (2) is the mass balance equation for the electrolyte ions, formula (3) is the potential equation for 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] q cell =q irrev +q rev =q act +q ohm +q rea +Q 相变 (8)

[0062] q act =S a,i jloc 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 represents 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 interfacial area between the electrode and the electrolyte; i 1 represents the positive current, i 1′ Represents the negative electrode current, i 2 represents the electrolyte current, represents the positive electrode potential, i 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 generation calculation formulas, and formula (12) is the boundary equation that uses natural convection and radiation to describe the heat dissipation behavior of 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 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=θ 1 ρ 1 +θ 2 ρ 2 (14)

[0069]

[0070]

[0071] k=θ 1 k 1 +θ 2 k 2 (17)

[0072] θ 1 +θ 2 =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; θ 1 and θ 2 Respectively represent the mass fraction of solid and liquid phase change materials; ρ 1 and ρ 2 Represent the density 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, Indicates the rate of change of the average thermal expansion coefficient with temperature; k 1 and k 2 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, the coupling of external short-circuit model, thermal model and phase change model as well as the prediction of temperature and heat can be realized through simulation software such as COMSOL.

[0075] In general, the temperature and heat prediction method for the liquid metal battery under external short-circuit conditions provided in this embodiment can predict the battery temperature and heat generation power (heat) through a model without conducting destructive and dangerous short-circuit experiments, and can estimate the thermal conditions of the battery electrolyte and electrode phase change, thereby improving the prediction accuracy of temperature and heat, which is beneficial to 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 condition is 50% SOC and a 0.5mΩ external short circuit resistor is connected. Figure 4 (b) is the temperature distribution cloud diagram of the liquid metal battery under the external short-circuit condition of 50% SOC and access to a 0.5mΩ external short-circuit resistor, 20s after the external short-circuit occurs; Figure 4 The predicted results shown 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 outer 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, the smaller the external short-circuit resistance, the greater the temperature rise rate. The simulation results are 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 shown indicate that this embodiment can accurately predict the temperature and heat of the liquid metal battery under external short-circuit conditions.

[0079] Embodiment 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 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 condition and the electrochemical mechanism of the liquid metal battery under the external short-circuit 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 the solid-liquid state is transformed into each other;

[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 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 a part of the heat generation rate of the battery in the thermal model;

[0083] And a prediction module is used to calculate the temperature and heat generation rate of the liquid metal battery at different times after an external short circuit occurs by using a coupling model, 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] Embodiment 3:

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

[0087] Embodiment 4:

[0088] A computer-readable storage medium includes 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 the temperature and heat prediction method under the external short-circuit condition of a liquid metal battery provided in the above-mentioned embodiment 1.

[0089] Embodiment 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 only 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 protection scope 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: According to the battery parameters of the liquid metal battery, an external short circuit model, a thermal model and a phase change model are respectively established; 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 condition and the electrochemical mechanism of the liquid metal battery under the external short circuit 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 the solid-liquid state is transformed into each other; 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 a part of the heat generation rate of the battery 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; jlo c 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; baudary1, baudary2, baudary3 and baudary4 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, Ic ell represents the battery current, σ1 represents the conductivity of the electrode; I ESC Represents 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 represents 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, i 1′ 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 condition and the electrochemical mechanism of the liquid metal battery under the external short circuit 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 the solid-liquid state is mutually transformed; A coupling module, used for coupling the external short-circuit model, the thermal model and the phase change model to obtain a coupling model; in the coupling 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 a part of the heat generation rate of the battery 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, so as to 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 It includes a computer program; when the computer program is executed by a processor, it implements the temperature and heat prediction method of the liquid metal battery under the external short-circuit condition as described in any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that: It includes 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 as described in 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 as described in any one of claims 1 to 4.

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