A method, system, and battery device for asymmetric control of a fully dissolved flow battery

Abstract

This invention provides an asymmetric control method, system, and battery device for a fully soluble flow battery, relating to the field of electrochemical energy storage technology. The method obtains the reaction kinetics and mass transfer parameters of the positive and negative electrodes through experimental testing, then inputs these parameters into a multiphysics coupled finite element model to simulate and analyze the performance bottlenecks of the two electrodes. Finally, it implements differentiated asymmetric control of electrode structure and operating conditions based on the kinetic advantages and disadvantages of the electrodes. This invention achieves precise matching of the reaction rate and mass transfer capacity of the two electrodes by establishing a closed-loop optimization system of parameter measurement, multiphysics simulation, asymmetric control, and experimental verification, significantly improving battery energy efficiency and power density, reducing ineffective energy consumption, and extending cycle life. The asymmetric control system for the fully soluble flow battery is applied to the asymmetric control method for fully soluble flow batteries. The fully soluble flow battery device is constructed based on the above-mentioned asymmetric control method.

Description

Technical Field

[0001] This invention relates to the field of electrochemical energy storage technology, and in particular to an asymmetric control method, system and battery device for a fully soluble flow battery. Background Technology

[0002] As the global energy structure accelerates its transition to renewable energy, the installed capacity of renewable energy sources such as wind and solar power continues to rise. However, their inherent intermittency and volatility pose a severe challenge to the stable operation of the power grid, making long-duration, large-scale energy storage technology a core support for solving this problem. Flow batteries, due to their advantages of independent power and capacity design, long cycle life, and high safety, have become one of the preferred technologies in the field of large-scale energy storage. Among them, the all-vanadium redox flow battery technology is the most mature, but its high vanadium resource price and unstable supply limit its large-scale promotion. New systems such as the fully dissolved all-iron flow battery, relying on abundant active elements, provide a new path for the low-cost development of flow batteries.

[0003] Existing fully soluble flow batteries generally employ a symmetrical electrode structure, meaning that key geometric parameters such as the thickness, porosity, and specific surface area of ​​the positive and negative electrodes are kept consistent. Simultaneously, symmetrical operating parameters, such as electrolyte circulation flow rate, electrolyte flow velocity within the electrodes, and operating current density, are all set without differentiation. Furthermore, the reaction kinetic parameters of the active materials in the positive and negative electrodes, such as reaction rate constants... The inherent differences cause the slower-kinetic-weighted electrode to become the performance bottleneck, exhibiting severe polarization, while the active interface of the faster-kinetic-weighted electrode is underutilized. At high current densities, this mismatch exacerbates concentration polarization, particularly on the kinetically disadvantaged side. Increasing the overall circulation flow rate to alleviate mass transfer limitations significantly increases pump power consumption and reduces system energy efficiency.

[0004] Meanwhile, existing optimization designs largely rely on literature or empirical parameters, lacking actual kinetic measurement data from real systems. This results in significant discrepancies between simulation predictions and actual performance, leading to unstable optimization effects. During long-term operation, the kinetically disadvantaged electrode, constantly exposed to high overpotential, experiences intensified side reactions, accelerated loss of active materials, and deterioration of the electrode structure, ultimately shortening battery life. Summary of the Invention

[0005] The purpose of this invention is to provide an asymmetric control method, battery device, and application for a fully soluble flow battery. Through a closed-loop system of experimental parameter measurement, multiphysics simulation, asymmetric control, and experimental verification, the reaction rate and mass transfer capacity of the two electrodes are precisely matched, thereby improving the battery's energy efficiency and power density. This solves key technical problems in existing fully soluble flow batteries, such as mismatch in positive and negative electrode reaction kinetics, excessive pump power loss, and rapid system life decay.

[0006] To achieve the above objectives, the present invention provides an asymmetric control method for a fully soluble flow battery, the method comprising: The reaction kinetics and mass transfer parameters of the positive and negative electrodes of the fully soluble flow battery were obtained based on experimental tests. The reaction kinetics parameters include the reaction rate constant, and the mass transfer parameters include the ion diffusion coefficient, the initial porosity of the electrode, the electrolyte viscosity, and the electrolyte density. The reaction kinetics parameters and mass transfer parameters are input into a multiphysics coupled finite element model to simulate the distribution of concentration field, electrochemical field and flow field inside the battery under different electrode structure parameters and operating conditions, so as to determine the matching difference between the mass transfer performance of the positive and negative electrodes and the reaction kinetics of the fully dissolved flow battery. The electrode structure parameters include: electrode thickness, electrode porosity and specific surface area, and the operating conditions parameters include: electrolyte flow rate, electrolyte flow velocity and current density. Based on the determined matching differences, the positive and negative electrodes of the fully soluble flow battery are asymmetrically controlled. The rationality and effectiveness of the control scheme were verified based on charge-discharge rate experiments.

[0007] Compared with existing technologies, the asymmetric control method for a fully soluble flow battery provided by this invention has the following beneficial effects: This invention obtains the reaction kinetic parameters and mass transfer parameters of the positive and negative electrodes of the fully soluble flow battery based on experimental testing. The reaction kinetic parameters include the reaction rate constant, and the mass transfer parameters include the ion diffusion coefficient, initial electrode porosity, electrolyte viscosity, and electrolyte density. The reaction kinetic parameters and mass transfer parameters are input into a multi-physics coupled finite element model to simulate the concentration field, electrochemical field, and flow field distribution inside the battery under different electrode structure parameters and operating conditions. This determines the matching difference between the mass transfer performance of the positive and negative electrodes of the fully soluble flow battery and the reaction kinetics. The electrode structure parameters include electrode thickness, electrode porosity, and specific surface area, and the operating conditions include electrolyte flow rate, electrolyte velocity, and current density. Based on the determined matching difference, asymmetric control is performed on the positive and negative electrodes of the fully soluble flow battery. Charge-discharge rate experiments are conducted on the controlled fully soluble flow battery to verify the rationality and effectiveness of the control scheme. This invention achieves precise matching of reaction rate and mass transfer capacity between two electrodes through a closed-loop optimization system involving experimental parameter measurement, multiphysics simulation, asymmetric control, and experimental verification. This significantly improves battery energy efficiency and power density, reduces ineffective energy consumption, and extends cycle life.

[0008] The present invention also provides an asymmetric control system for a fully soluble flow battery, the system comprising: The experimental testing module is used to obtain the reaction kinetic parameters and mass transfer parameters of the positive and negative electrodes of the fully soluble flow battery based on experimental testing. The reaction kinetic parameters include the reaction rate constant, and the mass transfer parameters include the ion diffusion coefficient, the initial porosity of the electrode, the electrolyte viscosity, and the electrolyte density. The model simulation module is used to input the reaction kinetics parameters and mass transfer parameters into a multiphysics coupled finite element model to simulate the distribution of concentration field, electrochemical field and flow field inside the battery under different electrode structure parameters and operating conditions, so as to determine the matching difference between the mass transfer performance of the positive and negative electrodes and the reaction kinetics of the fully soluble flow battery. The electrode structure parameters include: electrode thickness, electrode porosity and specific surface area, and the operating conditions parameters include: electrolyte flow rate, electrolyte flow velocity and current density. An asymmetric control module is used to perform asymmetric control on the positive and negative electrodes of a fully soluble flow battery based on the determined matching difference. The verification module is used to verify the rationality and effectiveness of the control scheme based on charge-discharge rate experiments.

[0009] Compared with the prior art, the asymmetric control system for a fully soluble flow battery provided by the present invention has the same beneficial effects as the asymmetric control method for a fully soluble flow battery provided by the above-mentioned technical solution, and will not be elaborated here.

[0010] The present invention also provides a fully soluble flow battery device, which is constructed using the steps in any of the above-described asymmetric control methods for fully soluble flow batteries, including a negative electrode assembly, a positive electrode assembly, a proton conduction membrane, an electrolyte storage and supply unit, and a current collection and conduction unit. The electrolyte storage and supply unit includes two independently configured storage tanks: a negative electrode storage tank for storing negative electrode electrolyte and a positive electrode storage tank for storing positive electrode electrolyte. The negative electrode assembly and the positive electrode assembly are asymmetric structures designed based on the difference in reaction kinetics between the positive and negative electrodes. The electrode assembly of the kinetically inferior electrode adopts an electrode porosity and electrode thickness structure adapted to supplement the reaction activity, while the electrode assembly of the kinetically superior electrode adopts an electrode porosity and electrode thickness structure adapted to enhance mass transfer performance. The electrolyte storage and supply unit also includes a negative electrode peristaltic pump and a positive electrode peristaltic pump, which are respectively connected to the negative electrode storage tank and the positive electrode storage tank. The output flow rates of the negative electrode peristaltic pump and the positive electrode peristaltic pump are set differently to match the mass transfer performance and reaction kinetics requirements of the corresponding electrodes. The proton-conducting membrane is located between the negative electrode assembly and the positive electrode assembly, allowing only protons to pass through, in order to achieve charge balance inside the battery and prevent cross-mixing of the positive and negative electrode electrolytes. The current collecting and conducting unit is electrically connected to the negative electrode assembly and the positive electrode assembly respectively, and is connected to an external load to form a complete charging and discharging circuit.

[0011] Compared with the prior art, the fully soluble flow battery device provided by the present invention has the same beneficial effects as the asymmetric control method for a fully soluble flow battery provided by the above-mentioned technical solution, and will not be elaborated here.

[0012] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 A schematic flowchart of an asymmetric control method for a fully soluble flow battery provided in Embodiment 1 of the present invention is shown. Figure 2 A schematic diagram illustrating the principle of an asymmetric control method for a fully soluble flow battery provided in Embodiment 1 of the present invention is shown. Figure 3 This shows a schematic diagram of the basic structure of the fully dissolved all-iron flow battery provided in Embodiment 1 of the present invention; Figure 4 This diagram illustrates a comparison of the distribution of active materials in the positive and negative electrodes of the fully dissolved all-iron flow battery before and after optimization, as provided in Embodiment 2 of the present invention. Figure 5 This diagram illustrates a comparison of the polarization curves and peak power density curves of the fully soluble all-iron flow battery before and after optimization, as provided in Embodiment 2 of the present invention. Figure 6 This diagram illustrates the rate test results of the fully soluble all-iron flow battery before and after optimization, as provided in Embodiment 2 of the present invention. Among them, 1 is the negative electrode, 2 is the positive electrode, 3 is the negative electrolyte storage tank, 4 is the positive electrolyte storage tank, 5 is the negative peristaltic pump, 6 is the positive peristaltic pump, 7 is the diaphragm, 8 is the negative current collector, and 9 is the positive current collector. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] In this embodiment, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Words such as "exemplary" or "for example" are used to indicate examples, illustrations, or explanations, intended to present related concepts in a specific manner, and should not be construed as superior or more advantageous than other embodiments or designs.

[0017] Existing fully soluble flow batteries generally employ symmetrical electrode structures for both positive and negative electrodes and undifferentiated operating conditions. This means that geometric parameters such as electrode thickness and porosity are kept consistent, and operating parameters such as electrolyte circulation flow rate and internal electrode flow rate are set uniformly. However, the reaction kinetic parameters of the active materials in the positive and negative electrodes inherently differ, leading to a series of technical drawbacks: Performance mismatch: The electrode with slower kinetics easily becomes a performance bottleneck, exhibiting severe polarization, while the active interface utilization of the electrode with faster kinetics is insufficient. During high current density operation, this mismatch exacerbates concentration polarization, and the mass transfer limitation problem of the weaker electrode is particularly prominent. Increasing the overall circulation flow rate would significantly increase pump power consumption and reduce system energy efficiency. Limitations of optimization schemes: Existing battery performance optimization relies heavily on literature or empirical parameters, lacking support from actual kinetic measurement data for real-world systems. This results in significant deviations between simulated predictions and actual performance, and insufficient stability of optimization effects. Limited lifespan: During long-term operation, the kinetically weaker electrode remains in a high overpotential state, significantly increasing the probability of side reactions, thereby accelerating the loss of active materials and electrode structure degradation, and significantly shortening the overall battery lifespan.

[0018] Example 1 Based on this, embodiments of the present invention provide an asymmetric control method for a fully soluble flow battery. Figure 1 The diagram shows a flow chart of an asymmetric control method for a fully soluble flow battery provided in an embodiment of the present invention. Figure 2 The diagram illustrates the principle of an asymmetric control method for a fully soluble flow battery provided in an embodiment of the present invention. Figures 1-2 As shown, the method includes: Step S1: Obtain the reaction kinetic parameters and mass transfer parameters of the positive and negative electrodes of the fully soluble flow battery based on experimental tests. The reaction kinetic parameters include the reaction rate constant, and the mass transfer parameters include the ion diffusion coefficient, the initial porosity of the electrode, the electrolyte viscosity, and the electrolyte density.

[0019] It should be noted that the reaction kinetics and mass transfer parameters of the positive and negative electrodes of the fully soluble flow battery were obtained based on systematic experimental testing.

[0020] Specifically, the negative electrode active material of the fully soluble flow battery includes vanadium, iron, titanium, sulfur, chromium, heteropolyacids, anthraquinone derivatives, phenolazine derivatives, and viologen derivatives; the positive electrode active material includes vanadium, iron, bromine, iodine, chromium, manganese, cerium, copper, heteropolyacids, ferrocene derivatives, and TEMPO derivatives. The fully soluble flow battery is constructed by combining any one or more of the negative electrode active materials with any one or more of the positive electrode active materials. For example, the fully soluble flow battery can be any one of an all-vanadium flow battery, a fully soluble all-iron flow battery, an iron-chromium flow battery, a vanadium-chromium flow battery, and an iron-vanadium flow battery.

[0021] Taking a fully soluble all-iron flow battery as an example, both its positive and negative electrolytes contain iron-active materials, chelating agents, and supporting electrolytes. The iron-active materials are provided by soluble trivalent iron salts, whose anions include, but are not limited to, chloride ions and ferricyanide ions, or one or more of these. The additives are one or more soluble compounds, whose cations are selected from one or more of Na+, K+, and Fe3+. The supporting electrolyte is provided by sodium / potassium ions, whose corresponding anions include, but are not limited to, sulfate ions, chloride ions, and perchlorate ions, or one or more of these. Sodium / potassium ions are used in the supporting electrolyte to adjust the pH of the solution and to improve the conductivity of the solution and maintain the osmotic pressure balance between the positive and negative electrolytes. The concentration of the iron salt is 0.1 mol / L to 1 mol / L, the additive concentration is 0.2 mol / L to 2 mol / L, and the concentration of sodium / potassium ions in the supporting electrolyte is 2 mol / L to 4 mol / L. The solvent is deionized water. The reaction principle of the positive and negative electrodes in an all-iron flow battery is as follows: negative electrode: , positive electrode: .

[0022] like Figure 3As shown, the basic structure of a fully soluble all-iron flow battery mainly includes: negative electrode 1, positive electrode 2, negative electrolyte storage tank 3, positive electrolyte storage tank 4, negative peristaltic pump 5, positive peristaltic pump 6, diaphragm 7, negative current collector 8, and positive current collector 9. The specific working principle of the fully dissolved all-iron flow battery is as follows: The negative electrolyte in the negative electrolyte storage tank 3 enters the negative electrode 1 through the negative electrode peristaltic pump 5. The active material in the negative electrolyte will undergo an electrochemical reaction on the surface of the negative electrode 1. After that, the negative electrolyte flows out of the negative electrode 1 and re-enters the negative electrolyte storage tank 3. The positive electrolyte in the positive electrolyte storage tank 4 enters the positive electrode 2 through the positive electrode peristaltic pump 6. The active material in the positive electrolyte will undergo an electrochemical reaction on the surface of the positive electrode 2. After that, the positive electrolyte flows out of the positive electrode 2 and re-enters the positive electrolyte storage tank 4. Because of the presence of the separator 7, the negative electrolyte on the surface of the negative electrode 1 and the positive electrolyte on the surface of the positive electrode are independent of each other. Only protons can pass through the separator. Both the negative current collector 8 and the positive current collector 9 are connected to the external load. Electrons are connected to the external circuit through the current collectors, forming a circuit.

[0023] To systematically evaluate the electrochemical performance of the electrode and electrolyte system, this embodiment employs a symmetrical battery testing device for performance characterization. Specifically, the symmetrical battery testing device uses a single storage tank to supply electrolyte to both the positive and negative electrodes, and the electrodes used for both electrodes are of the same type. Therefore, the positive and negative electrodes operate under completely symmetrical conditions. During the test, both electrodes of the symmetrical battery are supplied with electrolyte from the same storage tank to ensure consistent electrolyte concentration, composition, and temperature conditions, thereby eliminating the influence of asymmetric reaction factors on the experimental results.

[0024] As one possible implementation, this invention obtains the reaction kinetics and mass transfer parameters of the positive and negative electrodes of a fully soluble flow battery based on systematic experimental testing. Furthermore, the specific testing process for the reaction rate constant k is as follows: Symmetrical battery assembly and overall polarization testing: Symmetrical batteries were assembled using electrolyte with a state of charge (SOC) of 50%, and then steady-state polarization curves were tested using a charge-discharge tester. During the test, the electrolyte flow rate was maintained at 45 mL / min. For step current density, tests were performed sequentially. - The battery voltage at different current densities, the battery voltage measured for a symmetrical battery is the total polarization of the symmetrical battery.

[0025] Ohmic polarization determination: The Nyquist plot of the symmetrical cell is obtained by electrochemical impedance spectroscopy. The intercept of the curve with the horizontal axis in the high-frequency region represents the ohmic internal resistance of the cell. This resistance value can be obtained by fitting with Zview software. Ohmic polarization is the product of the applied current and the ohmic internal resistance of the cell.

[0026] Concentration polarization determination: The limiting current density is obtained by chronoamperometry, and the concentration polarization is calculated based on the limiting current density. Specifically, the concentration polarization is calculated using the concentration polarization formula based on the limiting current density. The concentration polarization formula is as follows: in, For concentration polarization, The gas constant is Thermodynamic temperature It is Faraday's constant. The effective reaction area of ​​the electrode. For operating current density, This represents the limiting current density.

[0027] Specifically, the limiting current density was obtained using a chronoamperometry method with an electrochemical workstation. During the test, the symmetric cell maintained an electrolyte flow rate of 45 mL / min and applied a step voltage, with a difference of 50 mV between two adjacent test potentials. Each voltage step was tested for at least 60 seconds until the current signal stabilized, thus yielding the limiting current density under the 45 mL / min flow rate condition. Substituting these values ​​into the concentration polarization formula above allows us to calculate concentration polarization at different current densities.

[0028] Activation polarization and rate constant determination: The total polarization characteristics were obtained through steady-state polarization curve testing, and further separated into three parts: ohmic polarization, concentration polarization, and activation polarization. Ohmic polarization was measured by impedance in the high-frequency region, concentration polarization was obtained by fitting the limiting current density, and activation polarization was obtained by subtracting the first two terms from the total polarization. Based on the total polarization of the symmetrical cell obtained from the total polarization test, ohmic polarization and concentration polarization were successively subtracted to obtain the activation polarization. The obtained activation polarization curve was then subjected to coordinate transformation to... Here, the x-axis is... Can It can also be ,by The vertical axis represents the ordinate. A Tafel linear fit is performed on the activation polarization linear region according to the Tafel equation. The exchange current density of the positive and negative electrodes can be obtained from the intercept of the fitted curve with the vertical axis. Specifically, the Tafel equations include: The negative electrode Tafel equation is as follows: And the positive electrode Tafel equation, the formula is: in, This is the activation overpotential of the negative electrode. This is the positive electrode activation overpotential. The negative cathode transfer coefficient. The positive electrode anode transfer coefficient, For exchange current density, The operating current density; When the reactant concentration equals the product concentration, the exchange current density... It can be simplified to: Where c is the concentration of the active substance when the concentrations of reactants and products are equal. It is Faraday's constant. Let k be the reaction rate constant. Therefore, the reaction rate constant k can be calculated.

[0029] As another possible implementation, to further reveal the mass transfer and structural behavior of the system, embodiments of the present invention conduct multi-dimensional physicochemical tests on the electrodes and electrolyte to obtain mass transfer parameters, including: Ion diffusion coefficient determination: Cyclic voltammetry was performed at different scan rates, such as 2 mV / s, 5 mV / s, 8 mV / s, and 10 mV / s, within a set voltage window, and the redox peak currents at each scan rate were recorded. .draw and the square root of the scan rate The relationship curve, where, The x-axis is... Using the vertical axis as the ordinate, the linear relationship between peak current and the square root of the scan rate is analyzed. The Randles-Sevcik equation is then used to fit the data, and the diffusion coefficient of active ions is calculated to characterize the ion mass transfer capacity of the electrolyte. Specifically, the Randles-Sevcik equation is as follows: in, Peak current, Where is the square root of the scan rate, and D is the ion diffusion coefficient. The effective reaction area of ​​the electrode. The number of electrons transferred in the electrode reaction. This represents the concentration of the active substance in its bulk.

[0030] Initial porosity determination of the electrode: By applying external pressure to the electrode to drive mercury to permeate into the porous structure, the relationship curve between mercury intrusion volume and pressure is obtained, and then the initial porosity, pore size distribution, and specific pore volume of the electrode are tested. Higher porosity and a reasonable pore size distribution help to enhance electrolyte wettability and ion diffusion efficiency.

[0031] Electrolyte viscosity and density determination: The dynamic viscosity of the electrolyte at different shear rates was measured using a rotational viscometer under isothermal conditions, such as 25 ± 0.5 °C. This parameter reflects the flow properties of the electrolyte and has a significant impact on ion diffusion rate and system energy efficiency. The electrolyte density was measured using a densitometer.

[0032] Step S2: Input the reaction kinetics parameters and mass transfer parameters into the multiphysics coupled finite element model to simulate the distribution of concentration field, electrochemical field and flow field inside the battery under different electrode structure parameters and operating conditions, so as to determine the matching difference between the mass transfer performance of the positive and negative electrodes of the fully dissolved flow battery and the reaction kinetics. The electrode structure parameters include: electrode thickness, electrode porosity and specific surface area. The operating conditions parameters include: electrolyte flow rate, electrolyte velocity and current density.

[0033] It should be noted that by inputting reaction kinetic parameters and mass transfer parameters into a multiphysics coupled finite element model, the distribution of concentration field, electrochemical field and flow field inside the battery is simulated under different electrode structure parameters and operating conditions. This allows for quantitative analysis of whether the mass transfer performance and reaction kinetics of the negative and positive electrodes of the fully soluble flow battery match under the existing symmetrical design, and the determination of the electrode with the inferior reaction kinetics and the electrode with the superior reaction kinetics.

[0034] The core governing equations of the multiphysics coupled finite element model include: The Butler-Volmor equation, which describes the electrochemical reactions on the electrode surface, is as follows: in, The negative electrode current density, The positive current density, The negative electrode exchange current density, The positive electrode exchange current density, The negative electrode anode transfer coefficient, The negative cathode transfer coefficient. The positive electrode anode transfer coefficient, The positive electrode cathode transfer coefficient, This is the negative overpotential. This is a positive overpotential; The Nernst-Planck equations describing the transport of charged particles are as follows: in, Let be the flux of i ions. The effective diffusion coefficient of ion i is given by... Let i be the concentration gradient of ions. Let i be the charge number of ion i. The effective mobility of i-ions, The potential gradient of the electrolyte phase. This is the electrolyte flow velocity vector. The bulk concentration of i ions; The Navier-Stokes equations describing electrolyte flow are as follows: in, The density of the electrolyte. Electrode porosity, This is the electrolyte flow velocity vector. Electrolyte pressure, The dynamic viscosity of the electrolyte. This represents the electrode permeability.

[0035] Taking an all-iron flow battery as an example, the electrolyte flow rate at both the positive and negative electrodes is 45 mL / min, the electrode porosity is 0.85, and the electrode thickness is 2.5 mm. The simulation results show that the battery's performance is generally poor under symmetrical electrode-operating conditions, and the distribution of active materials and current density within the battery is non-uniform.

[0036] The results of the test in step S1 show that the reaction rate constant of the negative electrode couple is The reaction rate constant of the positive electrode couple is This indicates that the reaction kinetics at the negative electrode are slower than those at the positive electrode, resulting in a faster reaction rate at the positive electrode and a faster consumption of active material. Under the same mass transfer conditions, the distribution of active material at the positive electrode is more uneven, while that at the negative electrode is more uniform. Conversely, the mass transfer performance and reaction kinetics performance at the negative electrode are not matched, leading to excess mass transfer and over-replenishment of active material. This also increases pump work loss, thereby reducing the overall system efficiency.

[0037] By comparing the distribution characteristics of active materials, current density distribution characteristics, charge-discharge performance, energy efficiency, and system efficiency inside the battery under a series of different flow rates, such as 15 ml / min, 30 ml / min, 45 ml / min, 60 ml / min, porosity, such as 0.75, 0.8, 0.85, 0.9, and electrode thickness, such as 1 mm, 2 mm, 3 mm, a series of rules were summarized: (1) As the electrolyte flow rate increases, the reactant concentration can be replenished in time, and the products can be discharged in time, resulting in a more uniform distribution of active materials. However, this also leads to an increase in pump power loss and a decrease in system efficiency. (2) Increasing the porosity will enhance the transport process of electrolyte inside the porous electrode, making the electrolyte distribution more uniform. Decreasing the porosity will increase the active sites on the porous electrode and enhance the reaction activity. Therefore, the regulation of porosity is an important part of balancing mass transfer and reaction kinetics. (3) Electrode thickness directly affects the electron transport path. Increasing the thickness will result in a longer electron transport path and a greater ohmic internal resistance. The advantage is that it can expand the electrolyte transport space and reduce pump power loss. Conversely, reducing the electrode thickness will compress the electrolyte transport space, requiring a greater pump power output to produce a stronger convection effect. At the same time, it will also shorten the electron transport path and reduce the ohmic internal resistance.

[0038] Step S3: Based on the determined matching differences, perform asymmetric control on the positive and negative electrodes of the fully soluble flow battery.

[0039] It should be noted that, based on the determined matching differences, for the electrode with the disadvantage in reaction kinetics, the electrode porosity is reduced to increase active sites, the electrode thickness is compressed to shorten the electron transport path, and a low electrolyte flow rate is matched to reduce pump power consumption; for the electrode with the advantage in reaction kinetics, the electrode porosity is increased to enhance mass transfer performance, the electrode thickness is compressed to reduce ohmic internal resistance, and an appropriate electrolyte flow rate is matched to balance mass transfer performance and pump power consumption, thereby achieving matching of mass transfer performance and reaction kinetics between the positive and negative electrodes of the fully soluble flow battery.

[0040] Specifically, based on the experimental test results in step S1 and the simulation results obtained in step S2, firstly, the porosity of the electrode with slower kinetics is reduced to 0.75 to increase the specific surface area and supplement its reactivity. The electrode thickness is compressed to 1 mm to obtain a shorter electron transport path, thereby reducing ohmic resistance. At the same time, the flow rate is appropriately reduced to 15 mL / min to reduce pump power loss, in order to compensate for the mismatch between mass transfer and the poor reaction kinetics and reduce polarization. Secondly, the porosity of the electrode with faster kinetics is adjusted to 0.8 to accelerate the transport of active substances and supplement its mass transfer performance. The electrode thickness is compressed to 1 mm to obtain a shorter electron transport path, thereby reducing ohmic resistance. At the same time, the flow rate is appropriately reduced to 30 mL / min to reduce pump power loss, in order to compensate for the mismatch between the faster reaction kinetics and the slower mass transfer process and reduce polarization.

[0041] Step S4: Based on the charge / discharge rate experiment, verify the rationality and effectiveness of the control scheme.

[0042] It should be noted that the above-mentioned asymmetric control scheme was verified using rate testing. By achieving a comprehensive balance between the reaction rate, concentration distribution, and flow resistance at both electrodes, the rationality of the asymmetric electrode-operating condition design was successfully verified. This process achieves complementarity and synergy in structural regulation and operating condition control, enabling the battery to maintain high voltage and energy efficiency at high power density and significantly extend cycle life.

[0043] Example 2 Taking an all-iron flow battery as an example, the specific preparation process of the negative electrode electrolyte is as follows: Dissolve 3.41g of ferric chloride hexahydrate, 5.34g of di(2-hydroxyethyl)iminotris(hydroxymethyl)methane (BIS-TRIS) and 6.60g of potassium hydroxide in 20ml of ultrapure water and stir for 24h. Then titrate the solution volume to 25ml.

[0044] The specific preparation process of the positive electrode electrolyte is as follows: Dissolve 4.89g of sodium ferrocyanide decahydrate and 1.995g of potassium ferrocyanide in 10ml of ultrapure water and stir for 10 minutes. Then add 1.21g of potassium hydroxide and stir for 24 hours. Finally, titrate the solution to 25ml.

[0045] Parameter testing includes, but is not limited to: ① measuring electrolyte viscosity using a viscometer; ② measuring electrolyte density using a densitometer; ③ measuring initial electrode porosimetry using a fully automated mercury porosimeter; ④ measuring electrode resistivity using a resistivity meter; ⑤ calculating the ion diffusion coefficient of the active material using cyclic voltammetry and the Randles-Sevcik equation; ⑥ assembling a symmetrical cell, calculating the activation polarization using electrochemical impedance spectroscopy, limiting current density testing, etc., and calculating k using the Tafel equation.

[0046] In the finite element model of a fully dissolved all-iron flow battery, the electrochemical reaction kinetics at the electrode surface can be represented by the Butler-Volmor equation: in, The negative electrode current density, The positive current density, The negative electrode exchange current density, The positive electrode exchange current density, The negative electrode anode transfer coefficient, The negative cathode transfer coefficient. The positive electrode anode transfer coefficient, The positive electrode cathode transfer coefficient, This is the negative overpotential. This is the positive overpotential.

[0047] Since the occurrence of electrochemical reactions is inseparable from the distribution of active substances, the diffusion, convection, and electromigration processes of charged particles in the electrolyte and electrodes can be represented by the Nernst-Planck equation: in, Let be the flux of i ions. The effective diffusion coefficient of ion i is given by... Let i be the concentration gradient of ions. Let i be the charge number of ion i. The effective mobility of i-ions, The potential gradient of the electrolyte phase. This is the electrolyte flow velocity vector. The bulk concentration of i ions.

[0048] Since convection plays a dominant role in mass transfer in flow batteries, the flow process of the electrolyte in the channels and electrodes can be represented by the Navier-Stokes equations: in, The density of the electrolyte. Electrode porosity, This is the electrolyte flow velocity vector. Electrolyte pressure, The dynamic viscosity of the electrolyte. This represents the electrode permeability.

[0049] The parameters obtained from experimental tests were input into a multiphysics coupled finite element model. The model was used to analyze the effects of different electrode-operating condition parameters, such as electrolyte flow rate, electrode porosity, and electrode thickness, on mass transfer and reaction kinetics. It was found that the negative electrode of the fully dissolved all-iron flow battery was limited by slow kinetics, leading to incomplete reaction. Therefore, the porosity of the negative electrode should be reduced to increase the specific surface area. The positive electrode has faster reaction kinetics, so some space for electrolyte reaction should be released to reduce pump power loss. Based on the evaluation indicators obtained from simulation calculations, such as energy efficiency, system efficiency, and power density, the electrode-operating condition parameters were repeatedly screened and iterated to achieve the expected targets. The final asymmetric design results, compared with the control group, showed that reducing the electrode thickness of both the positive and negative electrodes could compress the spatial distribution of the electrolyte in the electrodes to enhance convection. Simultaneously, the porosity of the negative electrode was reduced from 0.85 to 0.75 to provide more reaction sites to compensate for the slow reaction kinetics, while the porosity of the positive electrode was reduced from 0.85 to 0.8. This ensured sufficient reactive sites while effectively utilizing the pumping power of the electrolyte.

[0050] Figure 4 The diagram shows a comparison of the distribution of active materials in the positive and negative electrodes of the fully dissolved all-iron flow battery before and after optimization, as provided in Embodiment 2 of the present invention. Figure 4 As shown, the model calculations yielded and compared distribution cloud maps of reactants and products before and after optimization. The asymmetric design enabled full utilization of active materials within the battery, thus balancing mass transfer and reaction kinetics. Furthermore, we conducted data analysis on the power density curves before and after optimization, such as... Figure 5 As shown. The power density of the control group is only Asymmetric design batteries can achieve power density of This indicates a significant improvement in battery output performance. Furthermore, the optimized battery needs to be validated through experimental testing to demonstrate the rationality and feasibility of the strategy. Experiments were conducted using the simulated optimization parameters to test the battery's charge / discharge rate. Figure 6 The results show that the optimized battery The energy efficiency can reach 84% at the current density, which is significantly higher than the 78% energy efficiency of the control group, thus verifying the rationality and feasibility of the parameter control method and asymmetric electrode-operating condition design proposed in this invention.

[0051] Example 3 Taking a vanadium redox flow battery as an example, the preparation process of the positive electrode electrolyte is as follows: 25.6g of vanadium oxysulfate and 16.8ml of concentrated sulfuric acid are dissolved in 80ml of ultrapure water and stirred for 12 hours. The solution is then titrated to 100ml. The preparation process of the negative electrode electrolyte is as follows: 20ml of electrolyte is taken from each electrode of the battery, and constant current electrolysis is performed at 10mA / cm² until the battery voltage reaches 1.6V. At this point, the negative electrode side has the required negative electrode electrolyte.

[0052] The parameter testing process is the same as in Example 2. The parameters obtained from the experimental tests are input into the model, and the model is used to analyze the influence of different electrode-operating condition parameters, such as electrolyte flow rate, electrode porosity, and electrode thickness, on mass transfer and reaction kinetics.

[0053] Experimental results showed that the negative electrode reaction kinetics were relatively slow. Therefore, the negative electrode porosity was reduced from 0.9 to 0.85, while the positive electrode porosity remained unchanged. The electrolyte flow rates on both sides were increased from 15 ml / min to 45 ml / min to improve the electrolyte mass transfer efficiency. Battery charge-discharge rate experiments were conducted using the optimized parameters. The results showed that the optimized battery achieved an energy efficiency of 85% at a current density of 200 mA / cm², significantly higher than the 78% energy efficiency of the control group. This verifies the rationality and feasibility of the parameter control method and asymmetric electrode-operating condition design proposed in this invention.

[0054] Example 4 Taking an iron-chromium redox flow battery as an example, the electrolyte preparation process is as follows: 38.03g of ferrous chloride monohydrate, 93.25g of chromium chloride hexahydrate, and 52.52ml of hydrochloric acid are added to a certain amount of ultrapure water and stirred for 12 hours. The solution is then titrated to 250ml. 80ml of electrolyte is taken from each of the positive and negative electrodes for battery performance testing.

[0055] The parameter testing process was the same as in Example 2. The parameters obtained from the experimental tests were input into the model, and the model was used to analyze the influence of different electrode-operating condition parameters, such as electrolyte flow rate, electrode porosity, and electrode thickness, on mass transfer and reaction kinetics. Experimental results showed that the negative electrode reaction kinetics were relatively slow. Therefore, the negative electrode thickness was reduced from 3 mm to 1 mm (compression ratio of 66.7%), and the positive electrode thickness was reduced from 3 mm to 1.5 mm (compression ratio of 50%). The electrolyte flow rates on both sides were increased from 10 ml / min to 20 ml / min to improve the electrolyte mass transfer efficiency.

[0056] Experiments were conducted on the battery charge / discharge rate using the optimized parameters obtained through simulation. The results show that the optimized battery... The energy efficiency can reach 80% at the current density, which is significantly higher than the 75% energy efficiency of the control group, thus verifying the rationality and feasibility of the parameter control method and asymmetric electrode-operating condition design proposed in this invention.

[0057] Compared with the prior art, the asymmetric control method for a fully soluble flow battery provided in Embodiments 1 to 4 of the present invention has the following beneficial effects: 1. Based on the thorough determination of the reaction kinetics and mass transfer parameters of the active materials at the positive and negative electrodes of a fully soluble flow battery, this invention utilizes the obtained parameters to reveal the differences in electrochemical reaction rates, mass transfer capabilities, and polarization characteristics between the two electrodes. Based on this, asymmetric design and control of the electrode structure and operating conditions are implemented. By differentially adjusting the geometry, fluid distribution, and operating parameters of the two electrodes in structural design and operational control, the polarization of the weaker electrode is reduced, the utilization rate of the stronger electrode is improved, ineffective energy consumption is reduced, and system lifespan is extended, thereby effectively overcoming the performance bottleneck of fully soluble flow batteries.

[0058] 2. This invention, through a combination of experimental testing and numerical simulation, can reveal the differences between the two extremes based on a thorough understanding of reaction kinetics and mass transfer characteristics. Furthermore, it utilizes the model's rapid prediction capabilities to virtually screen and optimize different operating conditions. This approach not only avoids blind trial and error but also significantly improves the efficiency and accuracy of control. Therefore, this invention, while saving experimental time and material resources, achieves a scientific improvement in battery operating conditions, enabling fully soluble flow batteries to maintain stable electrochemical performance at higher power densities. It possesses significant practical value and widespread applicability.

[0059] 3. This invention experimentally determines the reaction kinetic parameters of the positive and negative electrode active materials, such as reaction rate constants and mass transfer parameters. These parameters are then input into a multiphysics coupled finite element model to achieve quantitative analysis of electrochemical reaction rates, mass transfer capabilities, and polarization characteristics. Based on experimental testing and parameter analysis, the reaction activity of the side with weaker reaction kinetics is improved, while the mass transfer performance of the side with faster reaction kinetics is improved, ultimately achieving a match between the positive and negative electrode reaction kinetics and mass transfer. This reveals the coupling law between electrode structure, flow state, and reaction kinetics, providing a systematic theoretical basis and optimization path for the asymmetric design of flow battery electrode structure and operating conditions.

[0060] 4. This invention, through asymmetric electrode-operating condition synergistic regulation, precisely improves the polarization phenomenon of the kinetically disadvantaged electrode and enhances the utilization rate of the active interface of the dominant electrode, breaking through the performance bottleneck of traditional symmetric designs and enabling the battery to maintain stable voltage and energy efficiency at high power density. Furthermore, by differentiating electrolyte flow rate matching, it avoids the problem of a surge in pump power consumption caused by indiscriminate flow rate increases, reducing system ineffective energy consumption. Simultaneously, it improves the long-term high overpotential operation of the disadvantaged electrode, reduces side reactions, delays active material loss and electrode degradation, extends battery cycle life, and significantly improves the overall electrochemical performance and long-term service reliability of the fully soluble flow battery energy storage system.

[0061] Example 5 The present invention also provides an asymmetric control system for a fully soluble flow battery, the system comprising: The experimental testing module is used to obtain the reaction kinetic parameters and mass transfer parameters of the positive and negative electrodes of the fully soluble flow battery based on experimental testing. The reaction kinetic parameters include the reaction rate constant, and the mass transfer parameters include the ion diffusion coefficient, the initial porosity of the electrode, the electrolyte viscosity, and the electrolyte density. The model simulation module is used to input the reaction kinetics parameters and mass transfer parameters into a multiphysics coupled finite element model to simulate the distribution of concentration field, electrochemical field and flow field inside the battery under different electrode structure parameters and operating conditions, so as to determine the matching difference between the mass transfer performance of the positive and negative electrodes and the reaction kinetics of the fully soluble flow battery. The electrode structure parameters include: electrode thickness, electrode porosity and specific surface area, and the operating conditions parameters include: electrolyte flow rate, electrolyte flow velocity and current density. An asymmetric control module is used to perform asymmetric control on the positive and negative electrodes of a fully soluble flow battery based on the determined matching difference. The verification module is used to verify the rationality and effectiveness of the control scheme based on charge-discharge rate experiments.

[0062] Compared with the prior art, the asymmetric control system for a fully soluble flow battery provided in Embodiment 5 of the present invention has the same beneficial effects as the asymmetric control method for a fully soluble flow battery provided in the above-mentioned technical solutions, and will not be described in detail here.

[0063] Example 6 This invention also provides a fully soluble flow battery device, which is constructed using the steps of any of the above-described fully soluble flow battery asymmetric control methods, including a negative electrode assembly, a positive electrode assembly, a proton conduction membrane, an electrolyte storage and supply unit, and a current collection and conduction unit. The electrolyte storage and supply unit includes two independently configured storage tanks: a negative electrode storage tank for storing negative electrode electrolyte and a positive electrode storage tank for storing positive electrode electrolyte. The negative electrode assembly and the positive electrode assembly are asymmetric structures designed based on the difference in reaction kinetics between the positive and negative electrodes. The electrode assembly of the kinetically inferior electrode adopts an electrode porosity and electrode thickness structure adapted to supplement the reaction activity, while the electrode assembly of the kinetically superior electrode adopts an electrode porosity and electrode thickness structure adapted to enhance mass transfer performance. The electrolyte storage and supply unit also includes a negative electrode peristaltic pump and a positive electrode peristaltic pump, which are respectively connected to the negative electrode storage tank and the positive electrode storage tank. The output flow rates of the negative electrode peristaltic pump and the positive electrode peristaltic pump are set differently to match the mass transfer performance and reaction kinetics requirements of the corresponding electrodes. The proton-conducting membrane is located between the negative electrode assembly and the positive electrode assembly, allowing only protons to pass through, in order to achieve charge balance inside the battery and prevent cross-mixing of the positive and negative electrode electrolytes. The current collecting and conducting unit is electrically connected to the negative electrode assembly and the positive electrode assembly respectively, and is connected to an external load to form a complete charging and discharging circuit.

[0064] Compared with the prior art, the fully soluble flow battery device provided in Embodiment 6 of the present invention has the same beneficial effects as the asymmetric control method for a fully soluble flow battery provided in the above technical solution, and will not be described in detail here.

[0065] Furthermore, this invention also provides an electronic device, including a bus, a transceiver, a memory, a processor, and a computer program stored in the memory and executable on the processor. The transceiver, the memory, and the processor are connected via the bus. When the computer program is executed by the processor, it implements the various processes of the above-described embodiment of the asymmetric control method for a fully soluble flow battery and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0066] Furthermore, this embodiment of the invention also provides a computer-readable storage medium storing a computer program thereon. When the computer program is executed by a processor, it implements the various processes of the above-described embodiment of the asymmetric control method for a fully soluble flow battery and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0067] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for asymmetric control of a fully soluble flow battery, characterized in that, Includes the following steps: The reaction kinetics and mass transfer parameters of the positive and negative electrodes of the fully soluble flow battery were obtained based on experimental tests. The reaction kinetics parameters include the reaction rate constant, and the mass transfer parameters include the ion diffusion coefficient, the initial porosity of the electrode, the electrolyte viscosity, and the electrolyte density. The reaction kinetics parameters and mass transfer parameters are input into a multiphysics coupled finite element model to simulate the distribution of concentration field, electrochemical field and flow field inside the battery under different electrode structure parameters and operating conditions, so as to determine the matching difference between the mass transfer performance of the positive and negative electrodes and the reaction kinetics of the fully dissolved flow battery. The electrode structure parameters include: electrode thickness, electrode porosity and specific surface area, and the operating conditions parameters include: electrolyte flow rate, electrolyte flow velocity and current density. Based on the determined matching differences, the positive and negative electrodes of the fully soluble flow battery are asymmetrically controlled. The rationality and effectiveness of the control scheme were verified based on charge-discharge rate experiments.

2. The asymmetric control method for a fully soluble flow battery according to claim 1, characterized in that, The reaction kinetics and mass transfer parameters of the positive and negative electrodes of the fully soluble flow battery obtained based on experimental testing include: The reaction rate constant is obtained through experimental testing, including the following steps: Assemble symmetrical cells and perform steady-state polarization curve tests on the symmetrical cells to obtain the total polarization under different current densities; Ohmic internal resistance is obtained by electrochemical impedance spectroscopy, and ohmic polarization is calculated based on ohmic internal resistance. The limiting current density was obtained by measuring the chronoamperometry, and concentration polarization was calculated based on the limiting current density. The activation polarization is obtained by subtracting ohmic polarization and concentration polarization from the total polarization. The exchange current density of the positive and negative electrodes of the symmetrical cell is obtained by linear fitting of the activation polarization, and the reaction rate constant is calculated. Mass transfer parameters were obtained through experimental testing, including: calculating the ion diffusion coefficient using multi-scan rate cyclic voltammetry combined with the Randles-Sevcik equation; testing the initial porosity of the electrode using mercury intrusion porosimetry; testing the electrolyte viscosity using a rotational viscometer; and testing the electrolyte density using a densitometer.

3. The asymmetric control method for a fully soluble flow battery according to claim 2, characterized in that, The calculation of concentration polarization based on the limiting current density includes: calculating the concentration polarization using a concentration polarization formula based on the limiting current density, wherein the concentration polarization formula is: ； in, For concentration polarization, The gas constant is Thermodynamic temperature It is Faraday's constant. The effective reaction area of ​​the electrode. For operating current density, The limiting current density; The process of obtaining the exchange current density of the positive and negative electrodes of the symmetrical cell by linear fitting of the activation polarization and calculating the reaction rate constant includes: obtaining the exchange current density of the positive and negative electrodes of the symmetrical cell by linear fitting of the activation polarization using the Tafel equation, wherein the Tafel equation includes the negative electrode Tafel equation, and the formula is as follows: ； And the positive Tafel equation, the formula is: ； in, This is the activation overpotential of the negative electrode. This is the positive electrode activation overpotential. The negative cathode transfer coefficient. The positive electrode anode transfer coefficient, For exchange current density, The operating current density; And the formula for calculating the reaction rate constant k is: ; Where c is the concentration of the active substance when the concentrations of reactants and products are equal. It is Faraday's constant. is the reaction rate constant.

4. The asymmetric control method for a fully soluble flow battery according to claim 2, characterized in that, The formula for the Randles-Sevcik equation is as follows: ； in, Peak current, Where is the square root of the scan rate, and D is the ion diffusion coefficient. The effective reaction area of ​​the electrode. The number of electrons transferred in the electrode reaction. This represents the concentration of the active substance in its bulk.

5. The asymmetric control method for a fully soluble flow battery according to claim 1, characterized in that, The reaction kinetics and mass transfer parameters are input into a multiphysics coupled finite element model to simulate the concentration field, electrochemical field, and flow field distribution inside the battery under different electrode structure parameters and operating conditions. This is to determine the matching differences between the mass transfer performance of the positive and negative electrodes and the reaction kinetics of the fully dissolved flow battery, including: The reaction kinetics and mass transfer parameters are input into a multiphysics coupled finite element model to simulate the distribution of concentration field, electrochemical field, and flow field inside the battery under different electrode structure parameters and operating conditions. This allows for quantitative analysis of the matching degree between the mass transfer performance of the positive and negative electrodes and the reaction kinetics of the fully soluble flow battery, identifying the electrode with the worst reaction kinetics and the electrode with the best reaction kinetics. The core governing equations of the multiphysics coupled finite element model include: The Butler-Volmor equation, which describes the electrochemical reactions on the electrode surface, is as follows: ； ； in, The negative electrode current density, The positive current density, The negative electrode exchange current density, The positive electrode exchange current density, The negative electrode anode transfer coefficient, The negative cathode transfer coefficient. The positive electrode anode transfer coefficient, The positive electrode cathode transfer coefficient, This is the negative overpotential. This is a positive overpotential; The Nernst-Planck equations describing the transport of charged particles are as follows: ； in, Let be the flux of i ions. The effective diffusion coefficient of ion i is given by... Let i be the concentration gradient of ions. Let i be the charge number of ion i. The effective mobility of i-ions, The potential gradient of the electrolyte phase. This is the electrolyte flow velocity vector. The bulk concentration of i ions; The Navier-Stokes equations describing electrolyte flow are as follows: ； in, The density of the electrolyte. Electrode porosity, This is the electrolyte flow velocity vector. Electrolyte pressure, The dynamic viscosity of the electrolyte. This represents the electrode permeability.

6. The asymmetric control method for a fully soluble flow battery according to claim 5, characterized in that, The asymmetric control of the positive and negative electrodes of the fully soluble flow battery based on the determined matching difference includes: Based on the determined matching differences, for the electrode with the disadvantage in reaction kinetics, the electrode porosity is reduced to increase active sites, the electrode thickness is compressed to shorten the electron transport path, and a low electrolyte flow rate is matched to reduce pump power consumption. For the electrode with the advantage in reaction kinetics, the electrode porosity is increased to enhance mass transfer performance, the electrode thickness is compressed to reduce ohmic internal resistance, and an appropriate electrolyte flow rate is matched to balance mass transfer performance and pump power consumption, thereby achieving matching of mass transfer performance and reaction kinetics between the positive and negative electrodes of the fully soluble flow battery.

7. The asymmetric control method for a fully soluble flow battery according to claim 1, characterized in that, The negative electrode active material of the fully soluble flow battery includes vanadium, iron, titanium, sulfur, chromium, heteropolyacids, anthraquinone derivatives, phenolazines derivatives, and viologen derivatives, while the positive electrode active material includes vanadium, iron, bromine, iodine, chromium, manganese, cerium, copper, heteropolyacids, ferrocene derivatives, and TEMPO derivatives. The fully soluble flow battery is composed of any one or more of the negative electrode active materials combined with any one or more of the positive electrode active materials.

8. An asymmetric control system for a fully soluble flow battery, characterized in that, include: The experimental testing module is used to obtain the reaction kinetic parameters and mass transfer parameters of the positive and negative electrodes of the fully soluble flow battery based on experimental testing. The reaction kinetic parameters include the reaction rate constant, and the mass transfer parameters include the ion diffusion coefficient, the initial porosity of the electrode, the electrolyte viscosity, and the electrolyte density. The model simulation module is used to input the reaction kinetics parameters and mass transfer parameters into a multiphysics coupled finite element model to simulate the distribution of concentration field, electrochemical field and flow field inside the battery under different electrode structure parameters and operating conditions, so as to determine the matching difference between the mass transfer performance of the positive and negative electrodes and the reaction kinetics of the fully soluble flow battery. The electrode structure parameters include: electrode thickness, electrode porosity and specific surface area, and the operating conditions parameters include: electrolyte flow rate, electrolyte velocity and current density. An asymmetric control module is used to perform asymmetric control on the positive and negative electrodes of a fully soluble flow battery based on the determined matching difference. The verification module is used to verify the rationality and effectiveness of the control scheme based on charge-discharge rate experiments.

9. The asymmetric control system for a fully soluble flow battery according to claim 8, characterized in that, The negative electrode active material of the fully soluble flow battery includes vanadium, iron, titanium, sulfur, chromium, heteropolyacids, anthraquinone derivatives, phenolazines derivatives, and viologen derivatives, while the positive electrode active material includes vanadium, iron, bromine, iodine, chromium, manganese, cerium, copper, heteropolyacids, ferrocene derivatives, and TEMPO derivatives. The fully soluble flow battery is composed of any one or more of the negative electrode active materials combined with any one or more of the positive electrode active materials.

10. A fully soluble flow battery device, characterized in that, The fully soluble flow battery is constructed using the asymmetric control method described in any one of claims 1-7, and includes a negative electrode assembly, a positive electrode assembly, a proton conduction membrane, an electrolyte storage and supply unit, and a current collection and conduction unit. The electrolyte storage and supply unit includes two independently configured storage tanks: a negative electrode storage tank for storing negative electrode electrolyte and a positive electrode storage tank for storing positive electrode electrolyte. The negative electrode assembly and the positive electrode assembly are asymmetric structures designed based on the difference in reaction kinetics between the positive and negative electrodes. The electrode assembly of the kinetically inferior electrode adopts an electrode porosity and electrode thickness structure adapted to supplement the reaction activity, while the electrode assembly of the kinetically superior electrode adopts an electrode porosity and electrode thickness structure adapted to enhance mass transfer performance. The electrolyte storage and supply unit also includes a negative electrode peristaltic pump and a positive electrode peristaltic pump, which are respectively connected to the negative electrode storage tank and the positive electrode storage tank. The output flow rates of the negative electrode peristaltic pump and the positive electrode peristaltic pump are set differently to match the mass transfer performance and reaction kinetics requirements of the corresponding electrodes. The proton-conducting membrane is located between the negative electrode assembly and the positive electrode assembly, allowing only protons to pass through, in order to achieve charge balance inside the battery and prevent cross-mixing of the positive and negative electrode electrolytes. The current collecting and conducting unit is electrically connected to the negative electrode assembly and the positive electrode assembly respectively, and is connected to an external load to form a complete charging and discharging circuit.

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