An electrochemical-thermal-lifetime coupling system for aqueous zinc-ion batteries

Abstract

The present invention relates to an electrochemical-thermal-life coupling model of an aqueous zinc ion battery, which belongs to the technical field of aqueous zinc ion batteries and is used to solve the problems of improving the method of relying on experimental trial and error in the development process of aqueous zinc ion batteries and improving the development efficiency. The method of the present invention utilizes the reaction mechanism of aqueous zinc ion batteries to construct an electrochemical-thermal coupling model of aqueous zinc ion batteries. In addition, since the Zn negative electrode has high electrochemical activity and thermodynamic instability in a mild aqueous electrolyte, the Zn negative electrode will react with H 2 O reacts to produce hydrogen, resulting in a decrease in the conductivity of the negative electrode surface. The continuous hydrogen evolution reaction consumes H + , causing local pH changes, promoting the formation of passivation on the electrode surface, seriously hindering uniform interfacial ion transport, and increasing the surface film resistance of the zinc negative electrode. A life coupling model is constructed based on the failure principle of aqueous zinc-ion batteries.

Description

Technical Field

[0001] The invention relates to the technical field of aqueous zinc ion batteries, and in particular to an electrochemical-thermal-lifetime coupling model of aqueous zinc ion batteries. Background Art

[0002] With the acceleration of global industrialization, environmental degradation and the reduction of fossil fuel reserves, people are increasingly in need of clean and renewable energy. After years of exploration and efforts, lithium-ion batteries have made great progress in energy density and power density. However, the global reserves of lithium are insufficient to meet future market demand, the price of raw materials is rising, and the organic electrolytes used in lithium-ion batteries are not only toxic, but also very easy to cause spontaneous combustion or even explosion when exposed to air. These shortcomings limit the widespread application of lithium-ion batteries.

[0003] Aqueous zinc-ion batteries have high energy density and power density, can be charged and discharged at high power, and have the advantages of easy preparation of electrode materials, low price, safety and environmental protection. They have become a research hotspot in the field of energy storage in recent years and have huge development potential and application prospects.

[0004] The prior art has not yet disclosed a model for the electrochemical-thermal-life coupling of aqueous zinc-ion batteries. The establishment of the model can guide the design of experiments, improve the method of relying on trial and error in the development process of aqueous zinc-ion batteries, and improve development efficiency. Summary of the invention

[0005] In view of the above analysis, the present invention aims to provide an electrochemical-thermal-lifetime coupling model for aqueous zinc-ion batteries, so as to solve the problems of improving the experimental trial-and-error method of aqueous zinc-ion batteries in the development process and improving the development efficiency.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] An electrochemical-thermal-lifetime coupling model for an aqueous zinc ion battery is constructed by the following method: Step S1: obtaining parameters required for modeling an aqueous zinc ion battery, and establishing an electrochemical-thermal coupling model for an aqueous zinc ion battery;

[0008] Step S2: Based on the life attenuation mechanism of the aqueous zinc ion battery and the electrochemical-thermal coupling model of the aqueous zinc ion battery, construct a negative electrode hydrogen evolution side reaction equation to obtain a life coupling model;

[0009] Among them, the negative electrode hydrogen evolution side reaction equation includes the equation for the reaction between the Zn negative electrode and H2O to produce hydrogen, the hydrogen generation rate equation, the time and hydrogen production equation, the conductivity and hydrogen production equation, and the zinc negative electrode surface film resistance and hydrogen production equation.

[0010] Furthermore, the equation for generating hydrogen by the reaction of the Zn negative electrode with H2O adopts the BV equation to describe the reaction of the Zn negative electrode with H2O to generate hydrogen, the equation for the generation rate of hydrogen adopts Faraday's law to describe the generation rate of H2, the equation for time and hydrogen production obtains the hydrogen production by integrating the time, the equation for conductivity and hydrogen production describes the decrease in conductivity due to hydrogen production, and the equation for the surface film resistance of the zinc negative electrode and hydrogen production describes the increase in the surface film resistance of the negative electrode due to hydrogen production.

[0011] Furthermore, in step S1, the parameters include geometric dimensions, thermodynamic parameters, kinetic parameters and thermal parameters of the battery.

[0012] Furthermore, step S1 further includes:

[0013] Step S11: establishing an electrochemical model according to the reaction mechanism of zinc ion deposition and dissolution at the negative electrode and zinc ion extraction and embedding at the positive electrode in the aqueous zinc ion battery;

[0014] Step S12: Establishing a thermal model based on heat transfer theory;

[0015] Step S13: constructing an electrochemical-thermal coupling model based on the coupling relationship between electrochemical-thermal characteristics;

[0016] Step S14: By comparing the experimental data of the aqueous zinc ion battery with the simulation data of the electrochemical-thermal coupling model, the parameters described in step S1 are optimized to obtain an optimized electrochemical-thermal coupling model.

[0017] Furthermore, in step S12, the thermal model is constructed using the energy conservation equation, taking into account the heat generation, heat transfer and heat dissipation inside the battery cell.

[0018] Furthermore, in step S13, an electrochemical-thermal coupling model is established based on the relationship between the heat generated by the electrochemical model and the temperature calculated by the thermal model.

[0019] Furthermore, based on the Arrhenius formula, the structure-activity relationship between the kinetic parameters of the internal part of the battery cell and the temperature is constructed to achieve full coupling between the electrochemical field and the temperature field.

[0020] Furthermore, the kinetic parameters include the positive electrode diffusion coefficient, the electrolyte diffusion coefficient, the positive and negative electrode exchange current density, and the negative electrode hydrogen evolution side reaction exchange current density.

[0021] Furthermore, in step S14, with the goal of making the maximum error between the battery experimental voltage and the model simulation voltage less than 50 mV, an iterative method is used to identify and optimize the parameters of the electrochemical-thermal coupling model.

[0022] Furthermore, the optimization includes positive electrode SOC reaction interval, positive electrode diffusion coefficient, positive and negative electrode conductivity and positive and negative electrode exchange current density, thereby improving the accuracy of the model.

[0023] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0024] The model of the present invention is used for the design of aqueous zinc ion batteries. The electrochemical-thermal coupling model constructed according to the working principle of aqueous zinc ion batteries can describe various physical and chemical processes inside aqueous zinc ion batteries, has high accuracy, optimizes battery design, and reduces development time and cost. The life prediction model is developed in combination with the failure mechanism of aqueous zinc ion batteries. The life coupling model can accurately predict the life of aqueous zinc ion batteries, clarify the influence of Zn negative electrode side reactions on the life of aqueous zinc ion batteries, and couple with the electrochemical-thermal model by influencing the negative electrode surface film resistance and negative electrode conductivity parameters. A kind of aqueous zinc ion battery electrochemical-thermal-life coupling model is constructed by this method, and then the model is further calibrated by experimental data to improve the accuracy of the model. When the model accuracy reaches the standard, the capacity, voltage and temperature of the battery can be predicted by adjusting the design parameters of the battery to guide the design of the battery.

[0025] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are only used for the purpose of illustrating specific embodiments and are not to be considered as limiting the present invention. In the entire drawings, the same reference symbols represent the same components;

[0027] Figure 1 A schematic flow chart of a method for constructing an electrochemical-thermal-lifetime coupling model for an aqueous zinc ion battery of the present invention;

[0028] Figure 2 This is a schematic diagram of the electrochemical model of the aqueous zinc ion battery of the present invention;

[0029] Figure 3 The schematic diagram of the change of positive electrode SOC during charging calculated by the electrochemical model of the present invention;

[0030] Figure 4 Calculate the negative electrode surface thickness curve during charging for the electrochemical model of the present invention;

[0031] Figure 5The schematic diagram of the change of positive electrode SOC during discharge calculated by the electrochemical model of the present invention;

[0032] Figure 6 Calculate the negative electrode surface thickness curve during discharge for the electrochemical model of the present invention;

[0033] Figure 7 A comparison diagram of the discharge curve experimentally measured under 0.1C discharge conditions of the present invention and the simulation results;

[0034] Figure 8 This is a comparison diagram of the experimental and simulation results under 1C discharge conditions of the present invention;

[0035] Fig. 9 This is a comparison chart between the simulation calculation results and the experimental results of the life coupling model constructed in Example 1 of the present invention. DETAILED DESCRIPTION

[0036] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0037] The model of the present invention is used for the design of aqueous zinc ion batteries. The electrochemical-thermal coupling model constructed according to the working principle of aqueous zinc ion batteries can describe various physical and chemical processes inside aqueous zinc ion batteries, has high accuracy, optimizes battery design, and reduces development time and cost. The life prediction model is developed in combination with the failure mechanism of aqueous zinc ion batteries. The life coupling model can accurately predict the life of aqueous zinc ion batteries, clarify the influence of Zn negative electrode side reactions on the life of aqueous zinc ion batteries, and couple with the electrochemical-thermal model by influencing the negative electrode surface film resistance and negative electrode conductivity parameters. A kind of aqueous zinc ion battery electrochemical-thermal-life coupling model is constructed by this method, and then the model is further calibrated by experimental data to improve the accuracy of the model. When the model accuracy reaches the standard, the capacity, voltage and temperature of the battery can be predicted by adjusting the design parameters of the battery to guide the design of the battery.

[0038] The method of the present invention utilizes that when an aqueous zinc ion battery is discharged, the metal zinc at the negative electrode loses electrons to become zinc ions, which move to the positive electrode through the electrolyte and are embedded in the positive electrode material; when charging, the zinc ions are released from the positive electrode material and move to the negative electrode to be deposited on the metal zinc. An electrochemical-thermal coupling model of an aqueous zinc ion battery is constructed according to the reaction mechanism of the aqueous zinc ion battery. In addition, since the Zn negative electrode has high electrochemical activity and thermodynamic instability in a mild aqueous electrolyte, the Zn negative electrode reacts with H2O to produce hydrogen, resulting in a decrease in the surface conductivity of the negative electrode. The continuous hydrogen evolution reaction consumes H +, causing local pH changes, promoting the formation of electrode surface passivation, seriously hindering uniform interface ion transmission, increasing zinc negative electrode surface film resistance, and constructing a life coupling model based on the failure principle of aqueous zinc ion batteries, and coupling it with the electrochemical-thermal model. The present invention involves many physical quantities in the specific implementation process. For ease of understanding, these physical quantities are presented in the form of Table 1a and Table 1b, and will not be listed one by one in the following.

[0039]

[0040]

[0041] A specific embodiment of the present invention, as Figure 1 As shown, an electrochemical-thermal-lifetime coupling model of an aqueous zinc ion battery is disclosed, and the model is constructed by the following method:

[0042] Step S1: Obtain the parameters required for modeling the aqueous zinc ion battery and establish an electrochemical-thermal coupling model of the aqueous zinc ion battery;

[0043] Step S2: Based on the life attenuation mechanism of the aqueous zinc ion battery and the electrochemical-thermal coupling model of the aqueous zinc ion battery, construct a negative electrode hydrogen evolution side reaction equation to obtain a life coupling model;

[0044] Among them, the negative electrode hydrogen evolution side reaction equation includes the equation for the reaction between the Zn negative electrode and H2O to produce hydrogen, the hydrogen generation rate equation, the time and hydrogen production equation, the conductivity and hydrogen production equation, and the zinc negative electrode surface film resistance and hydrogen production equation.

[0045] In a specific embodiment, the equation for the reaction of the Zn negative electrode with H2O to produce hydrogen uses the BV equation to describe the reaction of the Zn negative electrode with H2O to produce hydrogen, the hydrogen generation rate equation uses Faraday's law to describe the generation rate of H2, the time and hydrogen production equation uses the time integral to obtain the hydrogen production, the conductivity and hydrogen production equation describes the decrease in conductivity due to hydrogen production, and the zinc negative electrode surface film resistance and hydrogen production equation describes the increase in negative electrode surface film resistance due to hydrogen production.

[0046] Specifically, the conductivity and hydrogen production equation and the zinc negative electrode surface film resistance and hydrogen production equation in the present invention are semi-empirical formulas obtained by the inventors through a large number of experiments.

[0047] Specifically, the Zn negative electrode has high electrochemical activity and thermodynamic instability in a mild aqueous electrolyte. The Zn negative electrode reacts with H2O to produce hydrogen. The reaction is described by the Zn negative electrode reacting with H2O to produce hydrogen equation, as follows:

[0048] ;

[0049] The hydrogen generation rate equation obtained by Faraday's law is as follows:

[0050] ;

[0051] The time and hydrogen production equation is obtained by integrating the time, as follows:

[0052] ;

[0053] The generation of hydrogen on the negative electrode surface will affect the negative electrode surface conductivity, causing the negative electrode surface conductivity to decrease and will be related to the amount of hydrogen. The relationship between conductivity and hydrogen production is described by the conductivity and hydrogen production equation, as follows:

[0054] ;

[0055] Wherein, b is used to represent the conductivity reduction coefficient caused by hydrogen.

[0056] The hydrogen evolution reaction consumes H + , causing local pH changes, promoting the formation of passivation products on the electrode surface, and increasing the film resistance on the zinc negative electrode surface. The increase in film resistance is related to the amount of passivation products produced.

[0057] ;

[0058] From the above two equations, it can be seen that the amount of passivation products is related to the amount of hydrogen, and the relationship is 1 / 3. The surface film resistance is calculated by the zinc negative electrode surface film resistance and hydrogen production equation. The specific equation is as follows:

[0059] ;

[0060] Among them, c and d are the coefficients of increase in surface film resistance caused by passivation products, and b, c and d are calibrated according to relevant life experiments of the designed battery.

[0061] In a specific embodiment, in step S1, the parameters include geometric dimensions, thermodynamic parameters, kinetic parameters and thermal parameters of the battery.

[0062] Specifically, the geometric dimensions of the battery include particle level: positive electrode particle size and negative electrode particle size, which can be tested by a laser particle size analyzer; pole piece level: thickness, length and height of the positive pole piece, thickness, length and height of the negative pole piece, thickness, length and height of the separator, which can be measured by a micrometer;

[0063] The thermodynamic parameters mainly include the SOC-OCV curve of the positive electrode material and the equilibrium potential of the negative electrode material. The SOC-OCV curve of the material can be obtained by making a button-type half-cell and testing it at a very low rate;

[0064] Kinetic parameters mainly include conductivity, diffusion coefficient and reaction rate. Conductivity can be tested by a conductivity meter, diffusion coefficient can be calculated by the constant current intermittent titration technique (GITT) test of the battery, and reaction rate can be calculated by the electrochemical impedance spectroscopy (EIS) test;

[0065] The thermal parameters include density, specific heat capacity and thermal conductivity of the battery material.

[0066] In a specific implementation, step S1 further includes:

[0067] Step S11: establishing an electrochemical model according to the reaction mechanism of zinc ion deposition and dissolution at the negative electrode and zinc ion extraction and embedding at the positive electrode in the aqueous zinc ion battery;

[0068] Step S12: Establishing a thermal model based on heat transfer theory;

[0069] Step S13: establishing an electrochemical-thermal coupling model based on the relationship between the heat generated by the electrochemical model and the temperature calculated by the thermal model;

[0070] Step S14: By comparing the experimental data of the aqueous zinc ion battery with the simulation data of the electrochemical-thermal coupling model, the parameters described in step S1 are optimized to obtain an optimized electrochemical-thermal coupling model.

[0071] It should be noted that, due to the complicated mechanism of life attenuation, the inventors have found through a large number of experiments that hydrogen evolution is a more serious factor affecting life, so the present invention mainly considers the impact of hydrogen evolution. The electrochemical-thermal-life coupling model of the aqueous zinc ion battery of the present invention is a heat source obtained by solving the electrochemical model, which is transferred to the thermal model for solving the temperature, and the temperature is fed back to the electrochemistry to affect the electrochemical parameters of the battery. The temperature of the battery also affects the reaction rate of the battery side reaction. After the side reaction occurs, it will affect the change of the electrochemical parameters, resulting in an increase in battery polarization and affecting the battery life. The electrochemical model also affects the reaction rate of the side reaction, thereby realizing the mutual coupling between electrochemistry, heat and life.

[0072] Specifically, in step S11, the reaction mechanism of the aqueous zinc ion battery is different from that of the lithium ion battery. The aqueous zinc ion battery undergoes the following reaction during the charge and discharge process, and the deposition and dissolution of zinc ions occur at the negative electrode of the battery. The reaction equation is: ;

[0073] The main process of zinc ion extraction and embedding occurs at the positive electrode, and the reaction equation is:

[0074] ;

[0075] The corresponding electrochemical model was constructed based on the electrochemical theory of Newman et al., which included solid-phase ion diffusion, liquid-phase ion diffusion, solid-phase charge conservation, liquid-phase charge conservation and interface electrode reaction processes.

[0076] The control equations and boundary conditions for constructing the electrochemical model in the present invention are shown in Table 2.

[0077]

[0078] Specifically, Fick's second law is used to describe the diffusion process of zinc ions in solid particles and liquid phases, and the concentration of zinc ions in the solid phase and liquid phase can be obtained. The control equations and boundary conditions are shown in the zinc ion diffusion section of Table 2; the charge conservation is described by Ohm's law, and the current density and potential distribution are obtained. The control equations and boundary conditions are shown in the charge conservation section of Table 2; the charge reaction at the positive and negative electrode interfaces is described by the Butler-Volmer reaction kinetic equation, and its control equations and boundary conditions are shown in the interface charge reaction section of Table 2. After the interface charge reaction occurs on the surface of the negative electrode, the zinc ions will not be embedded in the negative electrode, but will undergo a deposition and dissolution reaction on the surface of the negative electrode, and the reaction rate is calculated by Faraday's law.

[0079] In a specific implementation, in step S12, the thermal model is constructed using the energy conservation equation, taking into account the heat generation, heat transfer and heat dissipation inside the battery cell.

[0080] Specifically, during the charge and discharge process of the battery, the internal electrochemical reaction of the battery generates heat, such as irreversible ohmic heat and reversible entropy heat, which will cause the internal temperature of the battery to rise. The reversible heat is caused by the entropy change of the material. At the same time, during the use process, the battery will dissipate heat through convection heat exchange with the environment. The heat generation equation and the heat dissipation equation are shown in Table 3.

[0081]

[0082] The Bernardi battery heat generation equation is used to describe the heat generation process of the battery, and the Newton heat dissipation equation is used to describe the heat dissipation of the battery.

[0083] In a specific embodiment, in step S13, an electrochemical-thermal coupling model is established based on the relationship between the heat generated by the electrochemical model and the temperature calculated by the thermal model.

[0084] Specifically, the heat generated by the electrochemical model is given to the thermal model to calculate the temperature. Changes in temperature will affect relevant parameters in the electrochemical reaction process, further affecting the electrochemical reaction, and establishing an electrochemical-thermal coupling model.

[0085] In a specific embodiment, the structure-activity relationship between the kinetic parameters of the internal part of the battery cell and the temperature is constructed based on the Arrhenius formula to achieve full coupling between the electrochemical field and the temperature field.

[0086] Specifically, the kinetic parameters include the positive electrode diffusion coefficient (ie, solid phase diffusion coefficient), the electrolyte diffusion coefficient (ie, liquid phase diffusion coefficient), the positive and negative electrode exchange current density (ie, reaction exchange current density), and the negative electrode hydrogen evolution side reaction exchange current density.

[0087] Specifically, the electrochemical model calculates the heat generation / heat generation rate of the battery cell and gives it to the thermal model to calculate the average temperature of the battery cell. The temperature is fed back to the electrochemical model to affect the rate of the chemical reaction through the Arrhenius equation.

[0088] In a specific implementation, in step S14, the maximum error between the battery experimental voltage and the model simulation voltage is less than 50 mV, and an iterative method is used to identify and optimize the parameters of the electrochemical-thermal coupling model.

[0089] Specifically, in the present invention, the parameters of the electrochemical-thermal coupling model are optimized by an iterative method until the maximum error between the battery experimental voltage and the model simulation voltage is less than 50 mV, and the optimal parameters are determined.

[0090] Specifically, the optimization includes the positive electrode SOC reaction interval, the positive electrode diffusion coefficient, the positive and negative electrode conductivity and the positive and negative electrode exchange current density, so as to improve the accuracy of the model.

[0091] Another specific embodiment of the present invention discloses a method for evaluating the life of an aqueous zinc ion battery using the above-mentioned battery electrochemical-thermal-life coupling model.

[0092] The technical solution of the present invention is further explained below in conjunction with specific embodiments.

[0093] Example 1

[0094] This example takes a manganese dioxide / zinc foil system soft-pack battery as an example, builds an electrochemical-thermal-life coupling model of an aqueous zinc ion battery according to the relevant parameters of the soft-pack battery, and calibrates the model through relevant experimental parameters to verify the accuracy and effectiveness of the model.

[0095] A method for constructing an electrochemical-thermal-lifetime coupling model for an aqueous zinc ion battery in this embodiment includes the following steps:

[0096] Step S11: Obtaining parameters required for modeling aqueous zinc ion batteries;

[0097] A soft pack battery was prepared with manganese dioxide as the positive electrode, zinc foil as the negative electrode, and 2M zinc sulfate as the electrolyte. The geometrical dimension parameters of the soft pack battery are shown in Table 4. The electrochemical parameters, battery thermodynamic parameters and kinetic parameters of the aqueous zinc ion battery were obtained through relevant tests. The relevant thermal parameters are shown in Table 5, and the relevant tests were carried out at an ambient temperature of 30°C.

[0098]

[0099]

[0100] Based on Newman's basic electrochemical model and the reaction principle of aqueous zinc-ion batteries, an electrochemical model of aqueous zinc-ion batteries was constructed. Figure 2 ). The model includes five equations: solid-phase ion diffusion, liquid-phase ion diffusion, solid-phase charge conservation, liquid-phase charge conservation, and interface electrode reaction. These five equations describe the positive electrode insertion and extraction and negative electrode deposition and dissolution processes during charge and discharge. The deposition and dissolution rate on the negative electrode surface is calculated using Faraday's law. Figures 3 to 6 The model calculates the schematic diagram of the change of positive electrode SOC and negative electrode surface thickness during charging and discharging. During the charging process, the battery voltage gradually rises, the positive electrode undergoes zinc removal reaction, and the positive electrode material SOC continues to decrease; the negative electrode undergoes Zn 2+ The ion deposition is the reaction of metal Zn, and the thickness of the negative electrode surface gradually increases. On the contrary, the discharge process has the opposite reaction, the positive electrode undergoes the reaction of embedding zinc, and the SOC of the positive electrode material continues to increase; the metal Zn dissolves into Zn at the negative electrode 2+ The reaction of ions and the thickness of the negative electrode surface gradually decreases. The model can accurately describe the charging and discharging process of aqueous zinc-ion batteries, proving the effectiveness of the model.

[0101] Step S12: Establishing a thermal model

[0102] The thermal model of aqueous zinc-ion battery is established according to the energy conservation equation. The heat includes reversible heat and irreversible heat. At the same time, the convective heat exchange with the environment is considered to dissipate heat. The control equation is shown in Table 3.

[0103] Step S13: constructing an electrochemical-thermal coupling model;

[0104] The heat generation / heat generation rate of the cell calculated by the electrochemical model is given to the thermal model to calculate the average temperature of the cell. The temperature is fed back to the electrochemical model to affect the relevant electrochemical parameters through the Arrhenius formula, thereby establishing an electrochemical-thermal coupling model. The relevant electrochemical parameters affected by temperature include the positive and negative electrode diffusion coefficients and the positive and negative electrode reaction rates. The specific formula is:

[0105] .

[0106] Where A is the relevant electrochemical parameter value at the temperature, A0 is the relevant electrochemical parameter value at the reference temperature, Ea is the activation energy of the relevant electrochemical parameter, R is the ideal gas coefficient, T ref is 25℃.

[0107] Step S14: Calibrate electrochemical parameters through experimental data to improve the accuracy of the model

[0108] The accuracy of the model is improved by calibrating certain electrochemical parameters through relevant experimental data. Specifically, the maximum error between the battery experimental voltage and the model simulation voltage is less than 50mV. It is iteratively calculated through an optimization algorithm. The optimization includes the positive electrode SOC reaction range, the positive electrode diffusion coefficient, the positive and negative electrode conductivity, and the positive and negative electrode exchange current density. The optimal parameter values ​​are obtained to obtain an optimized electrochemical-thermal coupling model.

[0109] The optimized electrochemical-thermal coupling model was used to simulate the battery's 0.1C and 1C discharges, and compared with experimental data under the same operating conditions to verify the accuracy of the model. Figure 7 This is a comparison chart of the discharge curve measured experimentally under 0.1C discharge conditions and the simulation results. It can be seen that under low current discharge conditions, the simulation results are highly consistent with the experimental results, with an error of less than 5mV. Figure 8 This is a comparison chart of the experimental and simulation results under 1C discharge conditions. Under high current discharge conditions, the simulation and experimental results are highly consistent, and the voltage error is less than 20mV.

[0110] Step S2: Based on the life attenuation mechanism of the aqueous zinc ion battery and the electrochemical-thermal coupling model of the aqueous zinc ion battery, construct a negative electrode hydrogen evolution side reaction equation to obtain a life coupling model;

[0111] The electrochemical-thermal-life coupling model of the aqueous zinc ion battery transfers the heat source obtained by solving the electrochemical model to the thermal model for solving the temperature, and the temperature is fed back to the electrochemistry to affect the electrochemical parameters of the battery. The temperature of the battery also affects the reaction rate of the battery side reaction; after the side reaction occurs, it will affect the electrochemical parameters, and the electrochemical model will also affect the reaction rate of the side reaction, thereby realizing the mutual coupling between electrochemistry, heat and life;

[0112] The negative electrode hydrogen evolution side reaction equations include the equation for the reaction between the Zn negative electrode and H2O to produce hydrogen, the equation for the generation rate of hydrogen, the equation for time and hydrogen production, the equation for conductivity and hydrogen production, and the equation for zinc negative electrode surface film resistance and hydrogen production;

[0113] Specifically, the Zn negative electrode reacts with H2O to produce hydrogen gas, and the equation is as follows:

[0114] ;

[0115] The hydrogen generation rate equation is as follows:

[0116] ;

[0117] The time and hydrogen production equation is as follows: ;

[0118] The conductivity and hydrogen production equation is as follows:

[0119] ;

[0120] The equation of zinc negative electrode surface film resistance and hydrogen production is as follows:

[0121] ;

[0122] Among them, b=1000, c=6.5, d=200.

[0123] In the life coupling model constructed by the present invention, the equation of the negative electrode hydrogen evolution side reaction is added. The negative electrode hydrogen evolution side reaction causes a decrease in the negative electrode conductivity and an increase in the surface film resistance, resulting in an increase in the battery polarization. As the number of battery cycles increases, the capacity retention rate gradually decreases.

[0124] The simulation results of the life coupling model constructed according to this embodiment are compared with the experimental results. Fig. 9 As shown in the figure, under the same number of cycles, the error between the capacity retention experiment and the simulation results is less than 5%, and the lifetime coupling model has good accuracy.

[0125] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0126] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. An aqueous zinc ion battery electrochemical-thermal-life coupling system, characterized in that: The system is constructed by the following method: Step S1: Obtain the parameters required for modeling the aqueous zinc ion battery and establish an electrochemical-thermal coupling model of the aqueous zinc ion battery; Step S2: Based on the life attenuation mechanism of aqueous zinc ion batteries and the electrochemical-thermal coupling model of aqueous zinc ion batteries, construct a negative electrode hydrogen evolution side reaction equation to obtain a life coupling system; The negative electrode hydrogen evolution side reaction equation includes the equation for the reaction between the Zn negative electrode and H2O to produce hydrogen, the hydrogen generation rate equation, the time and hydrogen production equation, the conductivity and hydrogen production equation, and the zinc negative electrode surface film resistance and hydrogen production equation; Step S1 also includes: Step S11: establishing an electrochemical model according to the reaction mechanism of zinc ion deposition and dissolution at the negative electrode and zinc ion extraction and embedding at the positive electrode in the aqueous zinc ion battery; Step S12: Establishing a thermal model based on heat transfer theory; Step S13: constructing an electrochemical-thermal coupling model based on the relationship between the heat generated by the electrochemical model and the temperature calculated by the thermal model; Step S14: By comparing the experimental data of the aqueous zinc ion battery with the simulation data of the electrochemical-thermal coupling model, the parameters described in step S1 are optimized to obtain an optimized electrochemical-thermal coupling model.

2. The aqueous zinc ion battery electrochemical-thermal-lifetime coupling system according to claim 1, characterized in that: The equation for generating hydrogen by the reaction of the Zn negative electrode with H2O adopts the BV equation to describe the reaction of the Zn negative electrode with H2O to generate hydrogen, the equation for the generation rate of hydrogen adopts Faraday's law to describe the generation rate of H2, the equation for time and hydrogen production obtains the hydrogen production by integrating the time, the equation for conductivity and hydrogen production describes the decrease in conductivity due to the generation of hydrogen, and the equation for the surface film resistance of the zinc negative electrode and hydrogen production describes the increase in the surface film resistance of the negative electrode due to the generation of hydrogen.

3. The aqueous zinc ion battery electrochemical-thermal-lifetime coupling system according to claim 1, characterized in that: In step S1, the parameters include geometric dimensions, thermodynamic parameters, kinetic parameters and thermal parameters of the battery.

4. The aqueous zinc ion battery electrochemical-thermal-lifetime coupling system according to claim 1, characterized in that: In step S12, the thermal model is constructed using the energy conservation equation, taking into account the heat generation, heat transfer and heat dissipation inside the battery cell.

5. The aqueous zinc ion battery electrochemical-thermal-lifetime coupling system according to claim 1, characterized in that: In step S13, the structure-activity relationship between the kinetic parameters of the internal part of the battery cell and the temperature is constructed based on the Arrhenius formula to achieve full coupling between the electrochemical field and the temperature field.

6. The aqueous zinc ion battery electrochemical-thermal-lifetime coupling system according to claim 5, characterized in that: The kinetic parameters include the positive electrode diffusion coefficient, the electrolyte diffusion coefficient, the positive and negative electrode exchange current density, and the negative electrode hydrogen evolution side reaction exchange current density.

7. The aqueous zinc ion battery electrochemical-thermal-lifetime coupling system according to claim 1, characterized in that: In step S14, the parameters of the electrochemical-thermal coupling model are identified and optimized by an iterative method with the goal of making the maximum error between the battery experimental voltage and the model simulation voltage less than 50 mV.

8. The aqueous zinc ion battery electrochemical-thermal-lifetime coupling system according to claim 7, characterized in that: The optimization includes the positive electrode SOC reaction interval, the positive electrode diffusion coefficient, the positive and negative electrode conductivity and the positive and negative electrode exchange current density, so as to improve the accuracy of the model.

9. A method for evaluating the life of an aqueous zinc ion battery using the aqueous zinc ion battery electrochemical-thermal-life coupling system according to any one of claims 1 to 8.

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