CN-121980729-A - Method, system, equipment and medium for simulating electrode interface morphology evolution of liquid metal battery

CN121980729ACN 121980729 ACN121980729 ACN 121980729ACN-121980729-A

Abstract

The invention relates to the technical field of energy storage batteries, and discloses a method, a system, equipment and a medium for simulating the electrode interface morphology evolution of a liquid metal battery, which comprise the steps of firstly calculating current distribution in an electrode and an electrolyte according to external working conditions by constructing a multi-physical-field simulation model for coupling electrochemical reaction, substance transfer and a level set interface, and obtaining local current density at an anode-electrolyte interface by utilizing a Butler-Volmer kinetic equation; and finally, dynamically simulating the evolution process of the positive electrode interface morphology in the charge-discharge process by solving a level set equation driven by the deposition speed. The invention can effectively predict the deposition behavior of the solid intermetallic compound under different working conditions, and provides a key theoretical tool for understanding the internal short circuit mechanism of the battery and optimizing the stability of the battery.

Inventors

ZHU YONG
YANG CHANGLONG
WANG MINGWEI
PANG LINGRONG
Yuan Xianmei
MA XIAOHONG
FAN LEI
TANG XUEYONG
WANG XIUJING
TENG YANG
LIU XI
Long Junxu
LI JIN

Assignees

贵州电网有限责任公司

Dates

Publication Date: 20260505
Application Date: 20251128

Claims (10)

1. A method for simulating the evolution of the electrode interface morphology of a liquid metal battery is characterized by comprising the steps of, Constructing a simulation model of a liquid metal cell, the simulation model comprising an electrochemical reaction and mass transfer physical field, a level set physical field, and optionally a heat transfer and fluid flow physical field; In the charge and discharge process, applying external current density to the battery, and obtaining the current density at the anode-electrolyte interface according to the external working condition; Converting the current density at the positive electrode-electrolyte interface to a deposition rate of the intermetallic compound; substituting the deposition speed into a level set equation, and solving a level set function to obtain the positive electrode interface morphology.
2. A method of modeling the evolution of the electrode interface morphology of a liquid metal battery as defined in claim 1, wherein obtaining the current density at the anode-electrolyte interface comprises calculating the current distribution in the electrode and electrolyte by conservation of charge and ion transfer based on the applied external current density, and combining the interfacial electrochemical reaction kinetics model to obtain the current density at the anode-electrolyte interface.
3. The method for simulating the evolution of the electrode interface morphology of a liquid metal battery according to claim 2, wherein converting the current density at the anode-electrolyte interface into the deposition rate of the intermetallic compound comprises calculating the deposition rate of the intermetallic compound according to the current density at the anode-electrolyte interface and the electrochemical metering relationship to obtain the deposition rate.
4. The method for simulating the evolution of the electrode interface morphology of the liquid metal battery according to claim 3, wherein the step of obtaining the positive electrode interface morphology comprises the steps of using the deposition speed as a conveying speed, simulating the evolution of the interface by a level set method, and solving a level set function to obtain the positive electrode interface morphology.
5. A method for modeling the evolution of a liquid metal battery electrode interface morphology according to claim 4, wherein the current density at the positive electrode-electrolyte interface comprises, obtained according to the Butler-Volmer equation, Wherein j 0 is the exchange current density, η represents the overpotential of the positive electrode-electrolyte interface, For the electrode potential, the electrode potential is set, The electrolyte potential is used as the electric potential of the electrolyte, In order to balance the potential of the liquid, For a local positive current density, 、 As a result of the apparent transfer coefficient, The Faraday constant, R is the gas constant, and T is the temperature.
6. A method for modeling the evolution of a liquid metal battery electrode interface morphology according to claim 5, wherein the deposition rate comprises converting the current density at the positive electrode-electrolyte interface to a deposition rate of an intermetallic compound, Wherein, the For the deposition rate, n is the number of electrons participating in the reaction, For the molar mass of the intermetallic compound AB formed, The density of the intermetallic compound AB formed.
7. A method for modeling the evolution of a liquid metal battery electrode interface morphology according to claim 6, wherein the level set equation includes a deposition rate as a transport rate, the level set equation is expressed as, Wherein, gamma is a reinitialization parameter, ∇ is a divergence operator, The thickness parameter of the interface is given, and t is time; And solving the level set function phi to obtain the positive electrode interface morphology.
8. A liquid metal battery electrode interface morphology evolution simulation system, which is applied to the method for simulating the liquid metal battery electrode interface morphology according to any one of claims 1-7, and is characterized by comprising a parameter and working condition setting module, a multi-physical-field computing module, an interface evolution simulation module and a result post-processing and visualization module; the parameter and working condition setting module is responsible for defining and configuring initial inputs required by all simulations and providing basic parameters for the whole simulation; The multi-physical-field calculation module is responsible for physical process calculation of a core, and obtains interface current density for driving interface evolution by solving a plurality of partial differential equations through coupling; the interface evolution simulation module is responsible for executing the dynamic simulation of morphology evolution, converting the current density into the deposition speed, and directly calculating the real-time change of the interface morphology by using a level set method; and the result post-processing and visualization module is responsible for converting the numerical calculation result into graphs and data for visual analysis and understanding.
9. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor, when executing the computer program, implements the steps of a liquid metal battery electrode interface topography evolution simulation method according to any one of claims 1 to 7.
10. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of a liquid metal cell electrode interface topography evolution simulation method according to any one of claims 1 to 7.

Description

Method, system, equipment and medium for simulating electrode interface morphology evolution of liquid metal battery Technical Field The invention relates to the technical field of energy storage batteries, in particular to a method, a system, equipment and a medium for simulating the electrode interface morphology evolution of a liquid metal battery. Background In order to reduce the use of fossil energy and carbon dioxide emission and promote economic clean and sustainable development, traditional thermal power generation is gradually replaced by photovoltaic and wind power generation. However, due to the intermittent and fluctuating nature of clean energy sources such as wind, light, etc., large-scale electrical energy storage will take on a critical role in future electrical power systems. The liquid metal battery innovatively adopts liquid metal as an anode and a cathode, and inorganic molten salt as an electrolyte, has the advantages of long cycle life, intrinsic safety, low manufacturing cost and the like, and is a large-scale power energy storage technology with great application prospect. The liquid metal battery needs to be operated at high temperature (300-550 ℃) to melt the electrodes and electrolyte into a liquid state. However, at higher depths of discharge, high melting point solid intermetallic compounds are formed in the positive electrode. Taking the Li Bi system as an example, the melting point of metallic lithium is 180 ℃, the melting point of metallic bismuth is 272 ℃, and the melting point of intermetallic compound Li3Bi is as high as 1130 ℃. The change in interfacial morphology caused by deposition and growth of solid intermetallic compounds can have a significant impact on the stable operation of the battery and can cause internal shorting of the battery when severe. Therefore, the method has important significance in representing the interfacial morphology evolution of the liquid metal battery in the operation process, however, the liquid metal battery is operated under high-temperature and sealing conditions, experimental means such as in-situ X-ray tomography can hardly be realized, and numerical simulation becomes an important means for researching the electrode morphology evolution process. Disclosure of Invention In view of the existing problems, the invention provides a method, a system, equipment and a medium for simulating the evolution of the electrode interface morphology of a liquid metal battery. Therefore, the invention solves the technical problems of avoiding the difficulty of experimental characterization, realizing the simulation of electrode interface morphology evolution under different material systems, different battery structures, different capacities and different working conditions, and providing theoretical guidance for improving the stability of the battery and reducing the probability of internal short circuit. In order to solve the technical problems, the invention provides a method for simulating the electrode interface morphology evolution of a liquid metal battery, which comprises the steps of constructing a simulation model of the liquid metal battery, wherein the simulation model comprises an electrochemical reaction and substance transfer physical field, a level set physical field and an optional heat transfer and fluid flow physical field; In the charge and discharge process, applying external current density to the battery, and obtaining the current density at the anode-electrolyte interface according to the external working condition; Converting the current density at the positive electrode-electrolyte interface to a deposition rate of the intermetallic compound; substituting the deposition speed into a level set equation, and solving a level set function to obtain the positive electrode interface morphology. The method for simulating the electrode interface morphology evolution of the liquid metal battery comprises the steps of calculating current distribution in the electrode and the electrolyte through charge conservation and ion migration based on the applied external current density, and obtaining the current density at the interface of the positive electrode and the electrolyte by combining an interface electrochemical reaction kinetic model. The method for simulating the electrode interface morphology evolution of the liquid metal battery comprises the steps of converting the current density at the positive electrode-electrolyte interface into the deposition rate of the intermetallic compound, and calculating the deposition rate of the intermetallic compound according to the current density at the positive electrode-electrolyte interface and the electrochemical metering relationship to obtain the deposition rate. The method for simulating the evolution of the electrode interface morphology of the liquid metal battery is characterized by comprising the steps of using the deposition speed as the transport speed, simulating the evolution of t