Coordination regulation type high-stability aqueous organic flow battery and preparation method thereof

Abstract

The invention provides a coordination regulation and control type high-stability aqueous organic flow battery adaptive to thermal power energy storage frequency modulation and a preparation method of the coordination regulation and control type high-stability aqueous organic flow battery. The preparation method comprises the following steps: adding deoxidized deionized water into an organic anode active material and an anode coordination regulator, introducing inert gas, carrying out stirring treatment, adding a pH regulator to regulate the pH value of the solution, and carrying out stirring treatment to form an anode electrolyte; adding deoxidized deionized water into an organic cathode active material and a cathode coordination regulator, introducing inert gas, stirring, adding supporting electrolyte, and stirring to form cathode electrolyte; immersing an ion exchange membrane into the modification liquid, and stirring to obtain a modified membrane; soaking the modified membrane in an alkali metal solution to activate ion exchange sites; the method comprises the following steps: immersing an electrode into a doping solution for dispersion treatment, drying to obtain a doped electrode, and carrying out cyclic voltammetry activation in an H2SO4 solution by taking the doped electrode as a working electrode, a platinum sheet as a counter electrode and a saturated calomel electrode as a reference electrode.

Description

Technical Field

[0001] This disclosure belongs to the field of electrochemical energy storage technology, specifically relating to a coordination-regulated high-stability aqueous organic flow battery and its preparation method. Background Technology

[0002] With the large-scale development of power systems and the increasing proportion of renewable energy generation, the demand for frequency regulation services from the power grid is becoming increasingly stringent. Thermal power, as the core supporting power source of the current power grid, directly determines the frequency stability of the grid through its frequency regulation performance. Traditional thermal power frequency regulation mainly relies on the turbine speed control system of the unit itself. However, thermal power units have inherent defects such as large inertia, slow response (usually on the order of seconds), and low regulation accuracy, making it difficult to meet the current high requirements of the power grid for frequency regulation response speed (millisecond level) and regulation accuracy. Furthermore, frequent start-ups and shutdowns and load fluctuations significantly increase the energy consumption, wear and tear, and maintenance costs of thermal power units, shortening their service life.

[0003] The integration of energy storage technology with thermal power, resulting in a thermal power energy storage frequency regulation mode, has become a core solution to the aforementioned problems. This mode rapidly absorbs or releases electrical energy through energy storage devices, assisting thermal power units in achieving millisecond-level frequency regulation response, reducing unit load fluctuation frequency, and improving frequency regulation accuracy and economy. Among numerous energy storage technologies, flow batteries have become one of the preferred technologies for thermal power energy storage frequency regulation due to their advantages such as capacity and power decoupling, long cycle life, and high safety performance. Aqueous flow batteries, in particular, use water as the electrolyte solvent and are characterized by low cost, high safety (no risk of combustion or explosion), and environmental friendliness, making them more suitable for the safety and economic requirements of energy storage devices in thermal power scenarios.

[0004] However, existing aqueous flow batteries (especially aqueous organic flow batteries) still face numerous technical bottlenecks when adapted to thermal power energy storage frequency regulation scenarios, severely limiting their large-scale application: First, poor electrolyte stability. Thermal power energy storage frequency regulation requires frequent charge-discharge cycles (up to dozens of cycles per day). The organic active materials in existing aqueous organic flow batteries are prone to polymerization, oxidation, or reduction decomposition during cycling, leading to rapid electrolyte activity decay and low battery capacity retention. Typically, after several thousand cycles, the capacity retention drops below 80%, making it difficult to meet the requirements of thermal power frequency regulation for long-term stable operation of energy storage devices (usually requiring a cycle life of over ten thousand cycles); Second, insufficient ion selectivity and transport efficiency. Frequency regulation in thermal power plants places extremely high demands on the response speed of energy storage devices, requiring batteries with low internal resistance and high ion transport efficiency. However, the membrane materials used in existing aqueous organic flow batteries are mostly conventional perfluorosulfonic acid membranes or unmodified polymer membranes, which have poor ion selectivity and are prone to cross-penetration of active materials in the cathode and anode. This not only aggravates electrolyte degradation but also increases battery internal resistance and reduces charge and discharge response speed, making it difficult to match the millisecond-level response requirements of thermal power frequency regulation. Thirdly, the electrode catalytic activity is low. Frequent high-frequency charge and discharge require electrodes with excellent electrocatalytic activity to accelerate charge transfer reactions and reduce polarization losses. However, the commonly used graphite felt and carbon cloth electrodes in existing flow batteries have few active sites on their surfaces and limited electrocatalytic performance, resulting in severe polarization and insufficient power density at high current densities, which cannot meet the rapid charge and discharge requirements of thermal power frequency regulation. Fourthly, there are insufficient adaptability and economic efficiency. Some existing high-performance aqueous flow batteries rely on scarce metal active materials or toxic solvents, have complex manufacturing processes, high costs, and narrow range of core parameters, making it difficult to flexibly adjust them according to the frequency regulation capacity requirements of different thermal power units, thus limiting their large-scale application.

[0005] To address the aforementioned issues, existing technologies often improve the situation by optimizing single aspects such as electrode materials, improving membrane structure, or adjusting electrolyte concentration. However, they fail to fundamentally solve the problem of synergistic optimization of electrolyte stability, ion transport efficiency, and electrode catalytic activity. For example, some technologies enhance catalytic activity by doping the electrodes, but fail to simultaneously optimize electrolyte stability, resulting in rapid electrolyte degradation that still limits the overall battery life. Other technologies employ novel membrane materials to improve ion selectivity, but poor interfacial compatibility between the electrolyte and the membrane still leads to high internal resistance.

[0006] Therefore, developing an aqueous organic flow battery that combines high stability, high response speed, high adaptability, and economy is key to breaking through the bottleneck of thermal power energy storage frequency regulation technology and promoting its large-scale application. Summary of the Invention

[0007] This disclosure aims to at least address the shortcomings of existing aqueous organic flow batteries, such as poor electrolyte stability, insufficient ion selectivity, low electrode catalytic activity, and narrow adaptability, and to provide a coordination-regulated high-stability aqueous organic flow battery and its preparation method that is suitable for frequency regulation in thermal power energy storage.

[0008] One aspect of this disclosure provides a method for preparing a coordination-regulated, highly stable aqueous organic flow battery, the method comprising: Deoxygenated deionized water is added to the organic anode active material and anode coordination regulator, inert gas is introduced, and after the first stirring treatment, a pH adjuster is added to adjust the pH of the solution, and after the second stirring treatment, an anode electrolyte is formed. Deoxygenated deionized water is added to the organic cathode active material and cathode coordination regulator, inert gas is introduced, and the mixture is stirred for a third time. Then, a supporting electrolyte is added and stirred for a fourth time to form a cathode electrolyte. The ion exchange membrane is immersed in the modification solution and stirred to allow the ion exchange membrane to be grafted in situ. After washing, the modified membrane is obtained. The modified membrane is immersed in an alkali metal solution to activate ion exchange sites, and before battery assembly, the modified membrane is immersed in the cathode electrolyte and the anode electrolyte respectively to complete the interface pre-wetting. The electrode was dispersed by immersing it in a doping solution and then dried to obtain the doped electrode. The doped electrode was used as the working electrode, a platinum sheet as the counter electrode, and a saturated calomel electrode as the reference electrode. Cyclic voltammetry activation was performed in H2SO4 solution. The modified membrane, which has undergone interface pre-wetting, and the electrochemically activated electrode are assembled into a complete battery system according to the structure of a flow battery.

[0009] Optionally, the molar ratio of the organic anode active material to the anode coordination regulator is 1:(1~3); The molar ratio of the organic cathode active material to the cathode coordination modifier is 1:(1~2.5).

[0010] Optionally, both the organic anode active material and the organic cathode active material are any one of anthraquinones, iridoids, and phenazines; The anodic coordination modifier is any one of hydroxycarboxylic acids, amines, or aminocarboxylic acids.

[0011] Optionally, the organic cathode active material is any one of quinones or organic sulfonates; The cathode coordination modifier is any one of hydroxycarboxylic acids, amines, and aminocarboxylic acids; The supporting electrolyte is any one of alkali metal salts, alkaline earth metal salts, and phosphates.

[0012] Optionally, the temperature of the first stirring treatment is 35-55℃, the time is 20-40 min, and a pH adjuster is added to adjust the pH of the solution to 3-14. The time of the second stirring treatment is 2-4 h. The third stirring process includes: stirring at room temperature for 15-30 minutes, then raising the temperature to 40-50°C and continuing to stir for 1.5-3 hours. The fourth stirring process takes 20-40 minutes.

[0013] Optionally, the modified liquid is formed using the following method: The aminosilane coupling agent is dissolved in a mixture of ethanol and deionized water, and the pH is adjusted to 4-5 with glacial acetic acid to obtain the modified solution; and / or, The ion exchange membrane is a perfluorosulfonic acid membrane, a sulfonated polymer membrane, or an amino-functionalized composite membrane, and the thickness of the ion exchange membrane is 20-200 μm.

[0014] Optionally, the concentration of the alkali metal solution is 0.3-0.7 mol / L, and the immersion time of the modified membrane in the alkali metal solution is 1.5-2.5 h; The modified membrane is immersed in the cathode electrolyte and the anolyte for 10-14 hours respectively.

[0015] Optionally, the doping solution is formed by dissolving thiourea in deionized water, adding a dispersant and stirring to dissolve, thereby obtaining the doping solution.

[0016] Optionally, the scanning range for cyclic voltammetric activation in H2SO4 solution is -1.0 to 1.2 V, the scanning rate is 30-70 mV / s, and the cycle is 40-60 times.

[0017] In another aspect of this disclosure, a coordination-regulated high-stability aqueous organic flow battery is proposed, which is prepared using the preparation method described above.

[0018] This disclosure provides a coordination-regulated, high-stability aqueous organic flow battery adapted for frequency regulation in thermal power energy storage and its preparation method, which has the following advantages compared to the prior art: First, traditional aqueous organic flow batteries often use uncoordinated pure organic electrolytes, which are prone to poor stability due to organic molecule polymerization and oxidative deactivation; or they use unmodified membranes / electrodes, relying solely on physical composite assembly, which easily leads to problems such as poor interfacial compatibility and obstructed ion transport. This disclosure forms a stable coordination system by organic active materials and multidentate ligands, which can regulate the molecular electronic structure and inhibit polymerization deactivation. At the same time, coordination regulation, in-situ membrane modification, and electrode doping activation work synergistically to achieve simultaneous improvement in electrolyte stability, membrane ion selectivity, and electrode catalytic activity from a mechanistic perspective, overcoming the limitations of single-stage optimization. This process achieves simultaneous optimization of coordination regulation and multi-material synergy, breaking through the performance bottlenecks of traditional single systems or simple composites.

[0019] Secondly, addressing the issue that traditional flow battery fabrication processes often employ crude methods such as conventional dissolution and simple cleaning, resulting in poor membrane interface wettability, few electrode active sites, and consequently high internal resistance and short cycle life, this disclosure employs a "multi-toothed ligand pre-coordination" design. This design utilizes the chelation effect between ligands and organic active materials to construct a stable structure, reducing the loss of active sites. Combined with in-situ grafting modification of the membrane using an aminosilane coupling agent, the Donnan repulsion effect and interface wettability are enhanced. The composite sulfide doping electrode introduces more active sites, and the dual transport channels (electrolyte coordination system channel + membrane / electrode modification channel) synergistically improve ion / electron transport efficiency. The electrochemical performance far surpasses that of batteries fabricated using traditional processes. This process mechanism better meets the core requirements of high stability and high power for aqueous organic flow batteries.

[0020] Third, addressing the issue that some existing aqueous organic flow batteries rely on scarce active materials or toxic solvents, and have stringent process parameters and narrow applicability, the organic active materials, coordination modifiers, and supporting electrolytes used in this disclosure are all conventional industrial reagents. Polar organic solvents can be recycled and reused, and the coordination reaction and modification process do not require high-temperature and high-pressure equipment. Post-processing only requires simple water washing and purification. At the same time, the core parameters (molar ratio of active material to coordination agent 1:(1~3), pH 3-14, etc.) have a wide range of applicability and can be flexibly adjusted according to different scenarios such as energy storage and portable power supplies. This reduces energy consumption and cost from a mechanistic perspective, broadens the applicability range, and is more suitable for large-scale industrial production. Its economy and applicability are significantly improved through process mechanism optimization. Attached Figure Description

[0021] Figure 1 This is a flowchart illustrating the preparation method of a coordination-regulated high-stability aqueous organic flow battery according to a specific embodiment of this disclosure. Figure 2 The charge-discharge test curves for Embodiment 8 and Comparative Example 1 of this disclosure are shown below. Figure 3 The polarization curves and power density curves of Embodiment 5 and Comparative Example 2 of this disclosure are shown below. Figure 4 The CV cycle test graphs at 40mV / s are for Embodiment 3 and Comparative Example 3 of this disclosure; Figure 5 This is a 200-hour self-discharge test diagram of Embodiment 1 of this disclosure. Detailed Implementation

[0022] To enable those skilled in the art to better understand the technical solutions of this disclosure, the disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain this disclosure and represent a part of the embodiments of this disclosure, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the protection scope of this disclosure.

[0023] As shown in Figure 1, one aspect of this disclosure provides a method S100 for preparing a coordination-regulated, highly stable aqueous organic flow battery, specifically including the following steps S110~S160: S110. Add deoxygenated deionized water to the organic anolyte and anolyte coordination modifier, purge with nitrogen or argon inert gas for protection, heat to 35-55℃ and stir magnetically at 250-400 r / min for 20-40 min, add pH adjuster dropwise to adjust the pH of the solution to 3-14, continue stirring for 2-4 h to form a stable coordination system, dilute to 250 mL with deoxygenated deionized water, purge with inert gas for 20-30 min to remove bubbles, seal in a brown reagent bottle and store in a light-proof and oxygen-free environment to form the anolyte.

[0024] In some preferred embodiments, the molar ratio of the organic anode active material to the anode coordination modifier is (1~3):1.

[0025] As a further preferred embodiment, the content of organic anode active material can preferably be 5.0-20.0g, and the content of deoxygenated deionized water can preferably be 180-220mL.

[0026] In some other preferred embodiments, the organic anode active material may be anthraquinones, iridoids, phenazines, etc., with a mass concentration range of 5.0-20.0 g / 250 mL.

[0027] As further preferred options, anthraquinones may preferably include 2,6-dihydroxyanthraquinone or 2-aminoanthraquinone. Iridin derivatives may preferably include methyl iodine or ethyl iodine. Phenazine derivatives may preferably include methyl phenazine sulfate or neutral red.

[0028] In some other preferred embodiments, the anode coordination modifier is a polydentate ligand containing N and O, such as amines, hydroxycarboxylic acids, aminocarboxylic acids, etc.

[0029] As further preferred options, amines such as triethanolamine and triisopropanolamine are preferred. Hydroxycarboxylic acids such as citric acid, tartaric acid, and malic acid are preferred. Aminocarboxylic acids such as ethylenediaminetetraacetic acid and hypozoxytriacetic acid are preferred.

[0030] In step S110, organic active substances are chelated with multidentate coordination regulators, and N and O multidentate ligands (citric acid, ethylenediamine, etc.) form stable coordination structures with anthraquinone / zirconium active substances, thereby inhibiting polymerization and oxidative decomposition.

[0031] S120. Add deoxygenated deionized water to the organic cathode active material and cathode coordination regulator. Stir at room temperature for 15-30 min under inert gas protection, then raise the temperature to 40-50℃ and continue stirring for 1.5-3 h. Add supporting electrolyte and stir for 20-40 min until completely dissolved. Adjust the volume to 250 mL with deoxygenated deionized water, purge with inert gas for 20-30 min to remove oxygen, and then seal and store in the dark to obtain the cathode electrolyte.

[0032] In some preferred embodiments, the molar ratio of the organic cathode active material to the cathode coordination modifier is 1 to 2.5:1.

[0033] As a further preferred embodiment, the content of organic cathode active material can preferably be 6.0-22.0g, and the content of deoxygenated deionized water can preferably be 180-220mL.

[0034] In some other preferred embodiments, the organic cathode active material may be selected from quinones, organic sulfonates, etc., with a mass concentration range of 5.0-20.0 g / 250 mL.

[0035] As a further preferred option, quinones such as benzoquinone and naphthoquinone are preferred, and organic sulfonates such as sodium 1,4-naphthoquinone-2-sulfonate and sodium anthraquinone-2-sulfonate are preferred.

[0036] In other preferred embodiments, the cathode coordination modifier is also a polydentate ligand containing N and O, such as amines, hydroxycarboxylic acids, and aminocarboxylic acids.

[0037] As a further preferred option, amines such as ethylenediamine, triethanolamine, and triisopropanolamine are preferred; hydroxycarboxylic acids such as citric acid, malic acid, and tartaric acid are preferred; and aminocarboxylic acids such as ethylenediaminetetraacetic acid and hypotriacetic acid are preferred.

[0038] In some other preferred embodiments, the supporting electrolyte includes alkali metal salts, alkaline earth metal salts, and phosphates, with a concentration of 0.5-2.0 mol / L.

[0039] As a further preferred option, alkali metal salts such as sodium chloride (NaCl), potassium chloride (KCl), and lithium chloride (LiCl) are preferred; alkaline earth metal salts such as magnesium chloride (MgCl2) and calcium chloride (CaCl2) are preferred; and phosphates such as sodium phosphate (Na3PO4) and dipotassium hydrogen phosphate (K2HPO4) are preferred.

[0040] S130, In-situ amino grafting modification of ion exchange membrane: Immerse the pretreated ion exchange membrane in the modification solution and stir in a water bath at 40-55℃ for 2-3 hours to achieve in-situ amino grafting on the membrane surface. After removal, ultrasonically clean with ethanol for 15-25 minutes to remove unreacted modifier, and then rinse with deionized water until neutral.

[0041] In some preferred embodiments, the ion exchange membrane includes a perfluorosulfonic acid membrane, a sulfonated polymer membrane, or an amino-functionalized composite membrane, with a thickness of 20-200 μm.

[0042] In some other preferred embodiments, the ion exchange membrane can be pretreated before immersion in the modification solution. For example, the ion exchange membrane within the protection range can be selected, cut into sizes of 3×5cm to 5×7cm, and ultrasonically cleaned with acetone and ethanol for 20-30 minutes each time to remove surface oil and impurities. After rinsing with deionized water until neutral, it can be air-dried.

[0043] In some other preferred embodiments, the modified solution is formed by dissolving 1.5-3.5g of aminosilane coupling agent in a mixture of 80-120mL of ethanol and deionized water (volume ratio 1:1), and adding 0.3-1.2mL of glacial acetic acid to adjust the pH to 4-5 to obtain the modified solution.

[0044] As a further preferred option, the aminosilane coupling agent can preferably be KH550. The molecular end of this coupling agent is a primary amino group, which has high activity and is easy to graft onto the membrane surface and form hydrogen bonds or electrostatic interactions with subsequent electrolyte components (such as coordination modifiers). At the same time, the silanol bond generated after the hydrolysis of its ethoxy group can form a strong covalent bond (Si-O-Si or Si-OC) with the hydroxyl group on the membrane surface, thereby achieving stable grafting.

[0045] In step S130, the ion exchange membrane is modified by in-situ amino grafting, and the membrane surface is grafted with an aminosilane coupling agent (KH-550) to enhance the Donnan repulsion effect, reduce the cross-permeation of active substances, and improve the wettability of the membrane interface with the electrolyte.

[0046] S140, Electrode N / S co-doping treatment: Immerse the modified membrane in an alkali metal solution and soak it at room temperature for 1.5-2.5 hours to activate ion exchange sites, then store it in deionized water for later use.

[0047] It should be understood that before battery assembly, the modified membrane needs to be immersed in the cathode electrolyte and the anolyte for 10-14 hours respectively to complete the interface pre-wetting.

[0048] In some preferred embodiments, the concentration of the alkali metal solution is 0.3-0.7 mol / L.

[0049] S150, Electrochemical Activation Treatment: The electrode is immersed in a doping solution for dispersion treatment, and after drying, the doped electrode is obtained. The doped electrode is used as the working electrode, a platinum sheet as the counter electrode, and a saturated calomel electrode as the reference electrode. Cyclic voltammetric activation is performed in H2SO4 solution.

[0050] In some preferred embodiments, the electrode substrate can be selected from graphite felt, carbon cloth, carbon fiber paper, and N / S doped modified electrodes, with the size customized from 2×2cm to 5×5cm. Before use, the electrodes should be ultrasonically cleaned with deionized water for 15-25 minutes to remove surface dust and impurities, and then dried. The electrodes are then placed in a tube furnace, protected by nitrogen or argon gas, and heated to 400-600℃ at a heating rate of 2-10℃ / min. After annealing for 3-8 hours and cooling to room temperature, the surface is lightly sanded with sandpaper to remove the oxide layer and loose fibers.

[0051] In some other preferred embodiments, the dopant solution is formed as follows: 0.8-2.2g of thiourea (N, S source) is dissolved in 40-60mL of deionized water, 0.3-1.2g of dispersant is added and stirred to dissolve, the electrode is immersed in the dopant solution and ultrasonically dispersed for 20-40min, and then dried in a vacuum drying oven at 60-80℃ for 2-4h.

[0052] In some other preferred embodiments, the process parameters for cyclic voltammetric activation in H2SO4 solution are as follows: the concentration of H2SO4 solution is 0.3-0.7 mol / L, the scan range is -1.0~1.2V, the scan rate is 30-70mV / s, and the cycle is 40-60 times.

[0053] It should also be understood that after activation, each electrode needs to be rinsed with deionized water until neutral, dried, and then immersed in the corresponding electrolyte solution, sealed and soaked for 60-80 hours to ensure that the electrode fully absorbs the electrolyte solution.

[0054] In steps S140 and S150, the electrode is N / S co-doped and electrochemically activated. Thiourea is used as the dopant source, and high-temperature annealing introduces active sites such as pyridine N and thiophene S, thereby reducing the charge transfer energy barrier.

[0055] S160. The modified film, which has undergone interface pre-wetting, and the electrochemically activated electrode are assembled into a complete battery system according to the structure of a flow battery.

[0056] This disclosure utilizes anthraquinones, iologens, and other organic active materials, N- and O-containing multidentate ligands (amines, hydroxycarboxylic acids, etc.) as coordination modifiers, and alkali metal salts as supporting electrolytes. A stable coordination-type organic electrolyte is prepared via a "pre-coordination composite-inert gas protection preparation" process. A high-performance ion exchange membrane is then prepared by in-situ grafting modification using sulfonated polymer membranes as the base membrane and aminosilane coupling agents as modifiers. A highly active electrode is prepared using graphite felt as the substrate via an "N / S co-doping-electrochemical activation" process. Finally, an aqueous organic flow battery is assembled. The electrolyte in this battery exhibits good stability, and the modified membrane and electrolyte demonstrate good compatibility. In other words, this disclosure simultaneously addresses the three major issues of stability, transport efficiency, and catalytic activity through the synergistic effect of "coordination-controlled electrolyte + modified membrane + highly active electrode."

[0057] Another aspect of this disclosure proposes a coordination-regulated high-stability aqueous organic flow battery, which is prepared using the preparation method described above. For details, please refer to the above description and will not be repeated here.

[0058] The high-stability aqueous organic flow battery based on coordination regulation disclosed herein is suitable for thermal power energy storage and frequency regulation scenarios. It can be used as a supporting energy storage device for thermal power systems to achieve rapid storage and release of electrical energy, improve the response speed, accuracy and economy of thermal power frequency regulation, and can also be extended to general energy storage scenarios such as new energy consumption and grid peak regulation.

[0059] The preparation method of a coordination-regulated high-stability aqueous organic flow battery will be described below with specific examples: Example 1 Step 1: Preparation of anolyte: Take 8.5 g of organic anolyte 2,6-dihydroxyanthraquinone and 12.0 g of citric acid as a coordination modifier. The molar ratio of organic anolyte to anolyte coordination modifier is 1:1.2. Add 200 mL of deoxygenated deionized water, purge with argon gas for protection, heat to 45 °C and stir magnetically at 300 r / min for 30 min. Add pH adjuster dropwise to adjust the pH of the solution to 9, and continue stirring for 3 h to form a stable coordination system. Make up to 250 mL with deoxygenated deionized water, purge with inert gas for 25 min to remove bubbles, and seal in a brown reagent bottle for storage in the dark and oxygen-free environment. Preparation of cathode electrolyte: Take 10.0 g of 1,4-naphthoquinone-2-sulfonate sodium (organic cathode active material) and 9.0 g of ethylenediamine (coordination modifier), with a molar ratio of 1:1.1. Add 200 mL of deoxygenated deionized water, stir at room temperature for 20 min under inert gas protection, then raise the temperature to 45 °C and continue stirring for 2 h. Add 1.0 mol / L NaCl and stir for 30 min until completely dissolved. Make up the volume to 250 mL with deoxygenated deionized water, purge with inert gas for 25 min to remove oxygen, and then seal and store in the dark.

[0060] Step 2: In-situ amino grafting modification of ion exchange membrane: The membrane material selected for ion exchange membrane was sulfonated polyether ether ketone membrane (thickness 80μm), cut to a size of 4×6cm, and ultrasonically cleaned with acetone and ethanol for 25min / time to remove surface oil and impurities. After rinsing with deionized water to neutral, it was air-dried. Preparation of modification solution: 2.0g KH-550 was dissolved in 100mL of ethanol and deionized water mixture (volume ratio 1:1), and 0.6mL glacial acetic acid was added to adjust the pH to 4. The cleaned membrane was immersed in the modification solution and stirred in a 50℃ water bath for 2.5h to achieve in-situ amino grafting on the membrane surface. After removal, it was ultrasonically cleaned with ethanol for 20min to remove unreacted modifier, and then rinsed with deionized water to neutral. The modified membrane was immersed in 0.5mol / L alkali metal salt solution and soaked at room temperature for 2h to activate ion exchange sites. It was then stored in deionized water for later use. Before battery assembly, the membrane was immersed in the cathode and anolyte electrolytes for 12h each to complete the interface pre-wetting.

[0061] Step 3: The electrode was made of graphite felt (3×5cm). It was ultrasonically cleaned with deionized water for 20 minutes to remove surface dust and impurities, and then air-dried. The electrode was placed in a tube furnace under nitrogen or argon protection, heated to 500℃ at a rate of 5℃ / min, and annealed for 5 hours. After cooling to room temperature, the surface was lightly sanded with sandpaper to remove the oxide layer and loose fibers. A doping solution was prepared: 1.0g of thiourea was dissolved in 50mL of deionized water, and 0.6g of dispersant was added and stirred until dissolved. The electrode was immersed in the doping solution and ultrasonically dispersed for 30 minutes. After removal, it was dried in a vacuum drying oven at 70℃ for 3 hours. Using the doped electrode as the working electrode, a platinum sheet as the counter electrode, and a saturated calomel electrode as the reference electrode, cyclic voltammetry activation was performed in a 0.5mol / L H2SO4 solution. The scan range was -1.0~1.2V, the scan rate was 50mV / s, and the cycle was 50 times. After activation, the electrode was rinsed with deionized water until neutral, air-dried, and then immersed in the corresponding electrolyte. It was sealed and soaked for 72 hours to ensure that the electrode fully adsorbed the electrolyte.

[0062] Step 4: The modified membrane, which has undergone interface pre-wetting, and the electrochemically activated electrode are assembled into a complete battery system according to the structure of a flow battery.

[0063] The battery test current density in this example is 50 mA / cm². 2 .

[0064] Example 2 The battery fabrication process in this example is the same as in Example 1, with the following differences: Step 1: The organic anode active material is methyl violetin (10.0g), and the anode coordination regulator is triethanolamine (13.5g), with a molar ratio of 1:1.5; pH adjuster is added to adjust the solution pH=7, the preparation temperature is 40℃, the stirring time is 2.5h, and the inert gas is nitrogen. The supporting electrolyte is 0.8 mol / L KCl; the cathode active material is benzoquinone (7.2 g), and the cathode coordination modifier is citric acid (8.0 g), with a molar ratio of 1:1.3; Step 2: The ion exchange membrane material is Nafion 115 (50μm thick), modified with 2.5g KH-550; Step 3: The electrode is made of carbon cloth (2×4cm), doped with 1.5g of thiourea and electrochemically activated; the electrode is annealed at 480℃ for 4h.

[0065] The battery test current density in this example is 40 mA / cm². 2 .

[0066] Example 3 The battery fabrication process in this example is the same as in Example 1, with the following differences: Step 1: The organic anode active material is 2-aminoanthraquinone (9.2g), and the anode coordination regulator is tartaric acid (11.5g), with a molar ratio of 1:1.1; pH adjuster is added to adjust the solution pH=8, the preparation temperature is 50℃, the stirring time is 3.5h, and the inert gas is argon. The supporting electrolyte is 1.2 mol / L LiCl; the cathode active material is sodium anthraquinone-2-sulfonate (11.0 g), and the cathode coordination regulator is hyponitrotriacetic acid (9.5 g), with a molar ratio of 1:1.2; Step 2: The ion exchange membrane material is an aminated MOF / polyimide composite membrane (100 μm thick), modified with 3.0 g KH-550; Step 3: The electrode is an N / S doped graphite felt (3×4cm), which is doped with 1.2g of thiourea and electrochemically activated; the electrode is annealed at 520℃ for 6h.

[0067] The battery test current density in this example is 60 mA / cm². 2 .

[0068] Example 4 The battery fabrication process in this example is the same as in Example 1, with the following differences: Step 1: The organic anode active material is methyl phenazine sulfate (8.0 g), and the anode coordination regulator is ethylenediaminetetraacetic acid (14.0 g), with a molar ratio of 1:1.4; pH adjuster is added to adjust the solution pH=10, the preparation temperature is 38℃, the stirring time is 2 h, and the inert gas is nitrogen. The supporting electrolyte is 0.6 mol / L Na3PO4; the cathode active material is naphthoquinone (6.8 g), and the cathode coordination modifier is malic acid (7.8 g), with a molar ratio of 1:1.2. Step 2: The ion exchange membrane material is a sulfonated polysulfone membrane (60 μm thick), modified with 1.8 g of KH-550; Step 3: The electrode is made of carbon fiber paper (2×3cm), which is doped with 0.9g of thiourea and electrochemically activated; the electrode is annealed at 450℃ for 3.5h.

[0069] The battery test current density in this example is 30 mA / cm². 2 .

[0070] Example 5 The battery fabrication process in this example is the same as in Example 1, with the following differences: Step 1: The organic anode active material is methyl violetin (12.0 g), and the anode coordination modifier is triisopropanolamine (16.0 g), with a molar ratio of 1:1.6; pH adjuster is added to adjust the solution pH to 6, preparation temperature is 55℃, stirring time is 4 h; argon is used as the inert gas. The supporting electrolyte is 1.5 mol / L NaCl; the organic cathode active material is sodium 1,4-naphthoquinone-2-sulfonate (12.0 g), and the cathode coordination modifier is ethylenediamine (10.5 g), with a molar ratio of 1:1.3. Step 2: The membrane material is Nafion 212 (25μm thick), modified with 2.2g KH-550; Step 3: The electrode is a graphite felt (4×5cm), doped with 1.8g of thiourea and electrochemically activated; the electrode is annealed at 550℃ for 7h.

[0071] The battery test current density in this example is 70 mA / cm². 2 .

[0072] Example 6 The battery fabrication process in this example is the same as in Example 1, with the following differences: Step 1: The organic anode active material is 2,6-dihydroxyanthraquinone (10.0 g), and the anode coordination regulator is malic acid (13.0 g), with a molar ratio of 1:1.3; pH adjuster is added to adjust the solution pH to 11, the preparation temperature is 35℃, and the stirring time is 1.5 h; the inert gas is nitrogen. The supporting electrolyte is 0.7 mol / L MgCl2; the organic cathode active material is benzoquinone (8.0 g), and the cathode coordination modifier is triethanolamine (10.0 g), with a molar ratio of 1:1.4. Step 2: The membrane material is a sulfonated polyether ether ketone membrane (120 μm thick), modified with 2.8 g of KH-550; Step 3: The electrode is made of carbon cloth (3×3cm), doped with 1.1g of thiourea and electrochemically activated; the electrode is annealed at 420℃ for 3h.

[0073] The battery test current density in this example is 20 mA / cm². 2 .

[0074] Example 7 The battery fabrication process in this example is the same as in Example 1, with the following differences: Step 1: The organic anode active material used is Neutral Red (7.5g), and the anode coordination modifier is hyponitrotriacetic acid (12.5g), with a molar ratio of 1:1.5; pH adjuster is added to adjust the solution pH to 5, the preparation temperature is 42℃, and the stirring time is 2.5h; the inert gas is argon. Step 2: The supporting electrolyte is 1.1 mol / L K2HPO4; the organic cathode active material is sodium anthraquinone-2-sulfonate (9.5 g), and the cathode coordination regulator is tartaric acid (8.5 g), with a molar ratio of 1:1.1; Step 3: The membrane material is an aminated MOF / polyimide composite membrane (150 μm thick), modified with 1.6 g KH-550; the electrode is carbon fiber paper (2 × 5 cm), doped with 0.8 g thiourea and electrochemically activated; the electrode annealing temperature is 490℃ and the time is 4.5 h. The battery test current density in this example is 55 mA / cm². 2 .

[0075] Example 8 The battery fabrication process in this example is the same as in Example 1, with the following differences: Step 1: The organic anode active material is ethyl violetin (11.0g), and the anode coordination regulator is citric acid (14.5g), with a molar ratio of 1:1.4; pH adjuster is added to adjust the solution pH to 8.5, the preparation temperature is 52℃, and the stirring time is 3.5h; the inert gas is nitrogen. The supporting electrolyte is 1.3 mol / L NaCl; the cathode active material is naphthoquinone (7.5 g), and the cathode coordination regulator is ethylenediaminetetraacetic acid (11.0 g), with a molar ratio of 1:1.2. Step 2: The ion exchange membrane material is Nafion 117 (183 μm thick), modified with 3.2 g of KH-550; Step 3: The electrode is a graphite felt (3×6cm), which is doped with 2.0g of thiourea and electrochemically activated; the electrode is annealed at 580℃ for 6.5h.

[0076] The battery test current density in this example is 80 mA / cm². 2 .

[0077] Example 9 The battery fabrication process in this example is the same as in Example 1, with the following differences: Step 1: The organic anode active material is 2-aminoanthraquinone (8.8g), and the anode coordination regulator is triethanolamine (12.5g), with a molar ratio of 1:1.3; pH adjuster is added to adjust the solution pH to 12, the preparation temperature is 37℃, and the stirring time is 2h; the inert gas is argon. The supporting electrolyte is 0.9 mol / L CaCl2; the cathode active material is sodium 1,4-naphthoquinone-2-sulfonate (10.5 g), and the cathode coordination modifier is malic acid (9.0 g), with a molar ratio of 1:1.2. Step 2: The ion exchange membrane material is a sulfonated polysulfone membrane (70 μm thick), modified with 2.1 g KH-550; Step 3: The electrode is made of carbon cloth (4×4cm), doped with 1.3g of thiourea and electrochemically activated; the electrode is annealed at 440℃ for 3h.

[0078] The battery test current density in this example is 25 mA / cm². 2 .

[0079] Example 10 The battery fabrication process in this example is the same as in Example 1, with the following differences: Step 1: The organic anode active material is methyl phenazine sulfate (9.0 g), and the anode coordination modifier is tartaric acid (12.0 g), with a molar ratio of 1:1.6; pH adjuster is added to adjust the solution pH=4, preparation temperature is 48℃, stirring time is 4h; inert gas is nitrogen. The supporting electrolyte is 1.4 mol / L Na3PO4; the cathode active material is benzoquinone (7.6 g), and the cathode coordination modifier is triisopropanolamine (13.0 g), with a molar ratio of 1:1.5. Step 2: The ion exchange membrane material is a sulfonated polyether ether ketone membrane (90 μm thick), modified with 2.4 g of KH-550; Step 3: The electrode is made of carbon fiber paper (3×4cm), which is doped with 1.4g of thiourea and electrochemically activated; the electrode is annealed at 530℃ for 5.5h.

[0080] The battery test current density in this example is 65 mA / cm². 2 .

[0081] Example 11 The battery fabrication process in this example is the same as in Example 1, with the following differences: Step 1: The organic anode active material is methyl violetin (9.5g), and the anode coordination modifier is ethylenediaminetetraacetic acid (15.0g), with a molar ratio of 1:1.7; pH adjuster is added to adjust the solution pH to 7.5, the preparation temperature is 43℃, and the stirring time is 3h; the inert gas is argon. The supporting electrolyte is 0.8 mol / L NaCl; the cathode active material is sodium anthraquinone-2-sulfonate (10.2 g), and the cathode coordination modifier is triisopropanolamine (13.0 g), with a molar ratio of 1:1.3; Step 2: The ion exchange membrane material is an aminated MOF / polyimide composite membrane (110 μm thick), modified with 2.6 g KH-550; Step 3: The electrode is a graphite felt (2×5cm), doped with 1.6g of thiourea and electrochemically activated; the electrode is annealed at 510℃ for 5h.

[0082] The battery test current density in this example is 45 mA / cm². 2 .

[0083] Example 12 The battery fabrication process in this example is the same as in Example 1, with the following differences: Step 1: The organic anode active material is 2,6-dihydroxyanthraquinone (10.5g), and the anode coordination regulator is triisopropanolamine (17.0g), with a molar ratio of 1:1.5. A pH adjuster is added to adjust the solution pH to 10.5. The preparation temperature is 50℃, and the stirring time is 3.5h. The inert gas is nitrogen. The supporting electrolyte is 1.2 mol / L KCl; the cathode active material is naphthoquinone (8.2 g), and the cathode coordination regulator is hyponitrotriacetic acid (10.0 g), with a molar ratio of 1:1.4; Step 2: The membrane material is Nafion 115 (50μm thick), modified with 2.3g KH-550; Step 3: The electrode is made of carbon cloth (3×5cm), doped with 1.7g of thiourea and electrochemically activated; the electrode is annealed at 470℃ for 4h.

[0084] The battery test current density in this example is 75 mA / cm². 2 .

[0085] Comparative Example 1 This example has no coordination modifier: except that there is no citric acid at the anode and no ethylenediamine at the cathode, the other parameters are completely consistent with those in Example 1. That is, in the preparation of the anode electrolyte, only deoxygenated deionized water is added to 2,6-dihydroxyanthraquinone (8.5g), and in the preparation of the cathode electrolyte, only deoxygenated deionized water is added to 1,4-naphthoquinone-2-sulfonate sodium (10.0g), without any coordination regulation.

[0086] Comparative Example 2 The membrane in this example was not modified in situ, and the other parameters were completely consistent with those in Example 1. That is, the sulfonated polyether ether ketone membrane was not modified with KH-550 amino grafting and only underwent routine acid and alkali cleaning processes.

[0087] Comparative Example 3 The electrode in this example has no N / S doping or activation, and the remaining parameters are completely consistent with those in Example 1. That is, the graphite felt only undergoes conventional annealing and cleaning, and no thiourea doping or electrochemical activation process is performed.

[0088] Table 1 Results of each embodiment and comparative example

[0089] In summary, as shown in Table 1, the test data demonstrate that the coordination regulation system is the core of improving electrolyte stability and ion transport efficiency. For example, the capacity retention rate of all the above embodiments exceeded 93%, and the initial specific capacity reached 120-138 mAh / g, while the capacity retention rate of Comparative Example 1 without a coordination regulator was only 65.5%, and the initial specific capacity dropped to 110 mAh / g. This indicates that N and O-containing multidentate ligands (such as citric acid and ethylenediamine) can form stable chelate structures with organic active substances. On the one hand, this inhibits the polymerization and oxidative deactivation of organic molecules—for example, the quinone structure of anthraquinones is prone to dimerization in aqueous systems, and the coordination agent blocks the polymerization pathway by binding to the active site. On the other hand, the coordination system can regulate the redox potential of active substances, reduce charge transfer resistance, and simultaneously improve their solubility in aqueous systems, preventing crystallization and precipitation that could block ion channels. Furthermore, the introduction of ligands can optimize the ionic environment of the electrolyte and work in synergy with the supporting electrolyte to construct an efficient ion transport path, resulting in the battery internal resistance of the embodiments being less than 0.95Ω, which is far superior to 1.52Ω of Comparative Example 1.

[0090] Furthermore, please continue to refer to Table 1. The above test data also shows that in-situ amino modification of the membrane and N / S co-doping of the electrode synergistically optimize the battery interface characteristics. For example, the capacity retention rates of Comparative Example 2 (unmodified membrane) and Comparative Example 3 (undoped electrode) are 77.8% and 74.6%, respectively, and the coulombic efficiency is less than 92.5%, while the coulombic efficiency of the examples all exceed 95.7% and the internal resistance is less than 0.95Ω. In terms of membrane modification mechanism, the aminosilane coupling agent (KH-550) grafted onto the membrane forms amino sites on the membrane surface, enhancing ion selectivity through the Donnan repulsion effect, reducing cross-penetration between the cathode and anode active materials, and simultaneously improving the interfacial wettability between the membrane and the electrolyte, thus reducing interfacial impedance. Electrode N / S co-doping introduces heteroatom defects to form more active sites, enhancing electrocatalytic activity—thiourea, as the N and S source, forms pyridine N, pyrrole N, and thiophene S on the electrode surface after high-temperature annealing. These sites lower the redox reaction energy barrier of organic active materials, accelerate charge transfer, and simultaneously enhance the electrode's adsorption capacity for the electrolyte, resulting in a stable electrolyte layer on the electrode surface, ensuring continuous and efficient reaction. The synergistic effect of these two factors enables the maximum current density in the examples to reach 112-140 mA / cm². 2 It is significantly better than the comparative example of 85-100 mA / cm 2 .

[0091] Furthermore, please refer to Table 1. The above embodiments also illustrate how matching process parameters broadens battery adaptability and industrialization potential. For example, the 12 embodiments cover different organic active materials, ligands, membrane materials, and electrode types, yet all exhibit excellent consistency performance, proving that the parameter range design of this scheme is scientifically sound and reasonable. From a mechanistic perspective, this invention, through the wide range of adaptation of key parameters such as the "active material-ligand" molar ratio of 1:(1~3), electrolyte pH (3-14), and membrane thickness (20-200μm), allows for flexible adjustment of combinations according to the needs of different application scenarios (such as energy storage and portable power supplies). For high-power scenarios, violet-based active materials + thin Nafion membranes can be selected, while for high-stability scenarios, anthraquinone-based active materials + aminated composite membranes can be selected. Meanwhile, all materials are conventional industrial reagents, the process does not require high temperature and high pressure, the membrane modification and electrode treatment steps can be replicated on a large scale, and the long cycle stability shown in the examples (retention rate of over 93% after 5000 cycles) has significantly reduced the industrialization cost and technical threshold, solving the core pain points of traditional aqueous organic flow batteries such as poor stability, narrow adaptability and difficulty in scaling up.

[0092] Furthermore, please refer to Figure 2The charge-discharge platform of Example 8 was more stable (voltage stabilized at around 0.8V) and had a higher specific capacity (above 20mAh / g), while the discharge platform of Comparative Example 1 showed a significant drop and a lower specific capacity. Mechanistically, the "organic active material-multidentate ligand" system of Example 8 formed a stable chelate structure, inhibiting the polymerization and deactivation of organic molecules. Simultaneously, the amino modification of the membrane and the N / S doping of the electrode synergistically optimized ion transport and interfacial reaction kinetics, resulting in low charge transfer resistance and a stable voltage platform during charge-discharge. In contrast, Comparative Example 1, lacking coordination regulation, was prone to dimerization of the organic active material, leading to the loss of active sites and a collapse of the charge-discharge platform.

[0093] Combined with the results in Table 1, it can be seen that: the traditional aqueous organic flow battery without coordination regulation (Comparative Example 1) retained only 65.5% of its capacity after 5000 cycles, with an initial specific capacity of 110 mAh / g and an internal resistance of 1.52 Ω; while the aqueous organic flow battery prepared in this invention (Example 8) achieved a capacity retention of 93.5% after 5000 cycles, with an initial specific capacity of 138 mAh / g, an internal resistance as low as 0.72 Ω, and a maximum current density increased to 140 mA / cm². 2 This provides a new path for the large-scale energy storage application of aqueous organic flow batteries.

[0094] Furthermore, please refer to Figure 3 In Example 5, the polarization curve has a smaller slope (lower internal resistance) and a higher peak power density, while in Comparative Example 2, the polarization is more severe and the power density decays faster. Mechanistically, the membrane in Example 5, after in-situ grafting modification with amino groups, exhibits enhanced Donnan repulsion at its surface amino sites, reducing cross-penetration of active materials and improving the interfacial wettability between the membrane and the electrolyte, thus lowering the interfacial impedance. In contrast, the unmodified membrane in Comparative Example 2 exhibits high interfacial impedance and poor ion selectivity, leading to intensified polarization and limited power density at high current densities.

[0095] Furthermore, please refer to Figure 4 In Example 3, the CV curve shows a larger redox peak current and a more symmetrical peak shape, while in Comparative Example 3, the peak current is smaller and the peak distortion is more obvious. Mechanistically, the N / S co-doped electrode in Example 3 exhibits enhanced electrocatalytic activity due to the formation of pyridine (N) and thiophene (S) defect sites on its surface, lowering the redox reaction energy barrier of organic active substances, resulting in a larger peak current and better reversibility in the CV curve. In contrast, the undoped electrode in Comparative Example 3 has fewer active sites, leading to slower reaction kinetics and consequently, a lower peak current and poorer reversibility.

[0096] Furthermore, please refer to Figure 5As shown in the figure, the voltage only slowly decreased from 1.2V to 0.8V within 200 hours, indicating an extremely low self-discharge rate. At the mechanistic level, the "coordination regulation + membrane amino modification" in Example 1 synergistically suppressed self-discharge—the coordination system stabilized the structure of the organic active material, reducing its dissolution and diffusion in the electrolyte; the amino sites of the membrane enhanced ion selectivity, blocking cross-penetration between the cathode and anode active materials, and avoiding direct reactions of the active materials. Therefore, the self-discharge rate was much lower than that of traditional aqueous organic flow batteries.

[0097] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. A method for preparing a coordination-regulated, highly stable aqueous organic flow battery, characterized in that, The preparation method includes: Deoxygenated deionized water is added to the organic anode active material and anode coordination regulator, inert gas is introduced, and after the first stirring treatment, a pH adjuster is added to adjust the pH of the solution, and after the second stirring treatment, an anode electrolyte is formed. Deoxygenated deionized water is added to the organic cathode active material and cathode coordination regulator, inert gas is introduced, and the mixture is stirred for a third time. Then, a supporting electrolyte is added and stirred for a fourth time to form a cathode electrolyte. The ion exchange membrane is immersed in the modification solution and stirred to allow the ion exchange membrane to be grafted in situ. After washing, the modified membrane is obtained. The modified membrane is immersed in an alkali metal solution to activate ion exchange sites, and before battery assembly, the modified membrane is immersed in the cathode electrolyte and the anode electrolyte respectively to complete the interface pre-wetting. The electrode was dispersed by immersing it in a doping solution and then dried to obtain the doped electrode. The doped electrode was used as the working electrode, a platinum sheet as the counter electrode, and a saturated calomel electrode as the reference electrode. Cyclic voltammetry activation was performed in H2SO4 solution. The modified membrane, which has undergone interface pre-wetting, and the electrochemically activated electrode are assembled into a complete battery system according to the structure of a flow battery.

2. The preparation method according to claim 1, characterized in that, The molar ratio of the organic anode active material to the anode coordination regulator is 1:(1~3); The molar ratio of the organic cathode active material to the cathode coordination modifier is 1:(1~2.5).

3. The preparation method according to claim 1, characterized in that, The organic anode active material is any one of anthraquinones, iolamines, or phenazines; The anodic coordination modifier is any one of hydroxycarboxylic acids, amines, or aminocarboxylic acids.

4. The preparation method according to claim 1, characterized in that, The organic cathode active material is any one of quinones or organic sulfonates; The cathode coordination modifier is any one of hydroxycarboxylic acids, amines, and aminocarboxylic acids; The supporting electrolyte is any one of alkali metal salts, alkaline earth metal salts, and phosphates.

5. The preparation method according to claim 1, characterized in that, The temperature of the first stirring treatment is 35-55℃, the time is 20-40 min, and the pH of the solution is adjusted to 3-14 by adding a pH adjuster. The time of the second stirring treatment is 2-4 h. The third stirring process includes: stirring at room temperature for 15-30 minutes, then raising the temperature to 40-50°C and continuing to stir for 1.5-3 hours. The fourth stirring process takes 20-40 minutes.

6. The preparation method according to claim 1, characterized in that, The modified liquid is formed using the following method: The aminosilane coupling agent is dissolved in a mixture of ethanol and deionized water, and the pH is adjusted to 4-5 with glacial acetic acid to obtain the modified solution; and / or, The ion exchange membrane is a perfluorosulfonic acid membrane, a sulfonated polymer membrane, or an amino-functionalized composite membrane, and the thickness of the ion exchange membrane is 20-200 μm.

7. The preparation method according to claim 1, characterized in that, The concentration of the alkali metal solution is 0.3-0.7 mol / L, and the modified membrane is immersed in the alkali metal solution for 1.5-2.5 hours. The modified membrane is immersed in the cathode electrolyte and the anolyte for 10-14 hours respectively.

8. The preparation method according to claim 1, characterized in that, The doping solution is formed by dissolving thiourea in deionized water, adding a dispersant and stirring to dissolve it, thus obtaining the doping solution.

9. The preparation method according to claim 1, characterized in that, The scanning range for cyclic voltammetric activation in H2SO4 solution is -1.0 to 1.2 V, the scanning rate is 30-70 mV / s, and the cycle is 40-60 times.

10. A coordination-regulated, highly stable aqueous organic flow battery, characterized in that, The coordination-regulated high-stability aqueous organic flow battery is prepared using the preparation method described in any one of claims 1 to 9.

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