An alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy, its preparation method, and its application.

Abstract

This invention discloses an alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy, its preparation method, and its application. It belongs to the field of alkaline zinc-based flow battery technology. The alkaline zinc-based flow battery electrolyte includes additives at a concentration of 0.01-1.5 mol / L; wherein the additives include one or more of sodium gluconate, sodium heptadate, triethanolamine, diethylenetriaminepentaacetic acid, bis(2-hydroxyethyl)amino(tris(hydroxymethyl)methane), aminotriacetic acid, hydroxyethylidene diphosphate, diethylenetriaminepentamethylene phosphoric acid, and ethylenediaminetetramethylene phosphoric acid. The electrolyte provided by this invention achieves a comprehensive improvement in the stability of the zinc anode interface and the cycle performance of the alkaline zinc-based flow battery. Furthermore, the method provided by this invention uses readily available raw materials, is simple to prepare, and is easy to promote and apply.

Description

Technical Field

[0001] This invention belongs to the field of alkaline zinc-based flow battery technology, and particularly relates to an alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy, its preparation method, and its application. Background Technology

[0002] Flow batteries, with their flexible design, high safety, and long lifespan, hold great promise for long-term, large-scale energy storage. Alkaline zinc-based flow batteries, in particular, have attracted significant attention from academia and industry in recent years due to their abundant zinc resources, low cost, and environmental friendliness. However, in actual operation, alkaline zinc-based flow batteries commonly face challenging issues such as uneven zinc deposition, hydrogen evolution, and self-corrosion side reactions on the zinc anode side. These problems severely restrict the commercial application of alkaline zinc-based flow batteries. Uneven zinc deposition is caused by multiple factors, including a lack of zinc-affinity nucleation sites on the electrode, a mismatch between zinc deposition kinetics and liquid phase mass transfer rates, and uneven local current density distribution. As charging progresses, dendrites generated by uneven zinc deposition can easily puncture the separator, leading to short-circuit failure. Dendrite detachment into the bulk solution causes capacity loss and affects the battery's cycle life. Because the deposition potential of zinc is lower than the reduction potential of water molecules, the hydrogen evolution reaction of water reduction occurs spontaneously along with zinc deposition. This reduces the coulombic efficiency of the battery, and the generated hydrogen is a flammable and explosive gas, affecting the cycle stability and safety of the battery system. Due to the small potential difference between different areas of the zinc surface deposited on the electrode, these areas will form local micro-cells. Zinc undergoes a self-corrosion and dissolution reaction at the anode active site of the micro-cell, resulting in battery capacity loss and impairing the battery's economic efficiency.

[0003] To address the aforementioned issues, existing technologies primarily focus on electrode structure design and membrane modification to improve the overall electrochemical performance of alkaline zinc-based flow batteries. However, electrode and membrane modification technologies are often limited by engineering bottlenecks such as complex preparation processes, high production costs, and difficulties in ensuring mass production consistency, hindering large-scale application. In contrast, electrolyte modification offers advantages such as ease of operation, low cost, and ease of large-scale preparation, making it a promising technological path for promoting the industrialization of alkaline zinc-based flow batteries. However, existing electrolyte additives often suffer from limitations such as limited regulatory functions, poor environmental compatibility, and insufficient chemical stability in alkaline systems. Therefore, providing a multifunctional zinc anode electrolyte additive that can simultaneously regulate uniform zinc deposition, suppress hydrogen evolution reaction, and mitigate zinc self-corrosion, while ensuring high safety and long-term chemical stability in alkaline environments, is of significant research value for overcoming the lifespan bottleneck of alkaline zinc-based flow batteries and promoting their large-scale commercial application.

[0004] Existing technologies CN202510710840.5, CN202510377104.2, and CN202510823472.5 improve battery performance by introducing additives into the traditional negative electrode electrolyte of alkaline zinc-iron / zinc-manganese flow batteries. However, they share a common characteristic: they remain within the framework of "solving a single problem." The selected electrolyte additives can only address some of the problems existing in the operation of specific alkaline zinc-based flow battery systems, failing to simultaneously achieve the multiple effects of regulating zinc deposition uniformity, suppressing hydrogen evolution and self-corrosion side reactions, and improving battery energy efficiency and long-cycle stability. In addition, the electrolyte environment of alkaline zinc-based flow batteries is usually a high-concentration alkaline solution, which places extremely high demands on the chemical stability of electrolyte additives. Many organic additives are prone to hydrolysis, degradation, or loss of activity under these strongly alkaline conditions.

[0005] Therefore, how to provide an alkaline zinc-based flow battery electrolyte that can achieve multiple effects such as regulating zinc deposition uniformity, suppressing hydrogen evolution and self-corrosion side reactions, and improving battery energy efficiency and long-cycle stability is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention proposes an alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy, its preparation method, and its application.

[0007] To achieve the above objectives, the present invention provides the following technical solution: An alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy includes zinc active material, supporting electrolyte, and additives. The concentration of the additive is 0.01-1.5 mol / L; the additive includes one or more of sodium gluconate, sodium heptadate, triethanolamine (TEOA), diethylenetriaminepentaacetic acid (DTPA), bis(2-hydroxyethyl)amino(tris(hydroxymethyl)methane) (BIS-TRIS), aminotriacetic acid (NTA), hydroxyethylidene diphosphate (HEDP), diethylenetriaminepentamethylene phosphate (DTPMP), and ethylenediaminetetramethylene phosphate (EDTMP).

[0008] Beneficial Effects: The additives used in this invention have densely distributed unbonded lone pairs of electrons and oxygen, nitrogen, and phosphorus atoms capable of coordinating with zinc active materials. Furthermore, the carboxylic acid groups (-COOH), phosphate groups (-PO3H2), or some hydroxyl groups (-OH) in their molecular structure can form corresponding anions through deprotonation, resulting in high solubility in alkaline environments. Simultaneously, the carbon-carbon, carbon-nitrogen, and carbon-phosphorus bonds in the molecular framework exhibit excellent resistance to hydrolysis and will not decompose or fail in strongly alkaline environments. This invention introduces novel multifunctional electrolyte additives into traditional electrolytes. By regulating the solvation structure of zinc active materials in the solution, it induces uniform zinc deposition; by reconstructing the hydrogen bond network in the solution using additive molecules, it suppresses hydrogen evolution side reactions; and by specifically adsorbing the additives onto the zinc anode, it forms an interfacial protective layer to suppress zinc self-corrosion side reactions, thereby significantly improving the interfacial stability of the zinc anode and ultimately enhancing the energy efficiency and cycle stability of the assembled alkaline zinc-iron flow battery.

[0009] Unlike existing technologies that focus on solving a single problem encountered during the operation of a particular alkaline zinc-based flow battery system, the additives selected in this invention not only improve zinc deposition but also inhibit hydrogen evolution and self-corrosion side reactions, further significantly improving the energy efficiency and long-cycle stability of the alkaline zinc-based flow battery. Therefore, this invention achieves a comprehensive improvement in both the stability of the zinc anode interface and the cycle performance of the alkaline zinc-based flow battery.

[0010] Preferably, the concentration of the zinc active substance is 0.1-1.5 mol / L; and the concentration of the supporting electrolyte is 3-5 mol / L.

[0011] Preferably, the zinc active material includes one or more of zinc chloride (ZnCl2), zinc bromide (ZnBr2), and zinc oxide (ZnO).

[0012] Beneficial Effects: The preferred zinc active material and supporting electrolyte of this invention offer multiple advantages in terms of their types and concentration ranges. Zinc chloride and zinc bromide exhibit good solubility, rapidly dissociating into zinc ions in solvents and subsequently forming a stable solvation structure with the preferred multifunctional electrolyte additives of this invention. Zinc oxide dissolves rapidly under strongly alkaline conditions to generate zincate ions, exhibiting excellent dissolution kinetics. Simultaneously, controlling the concentration of the zinc active material within the range of 0.1-1.5 mol / L ensures sufficient theoretical capacity of the electrolyte while avoiding the problem of supersaturation and precipitation of zinc active material at high concentrations. Limiting the concentration of the supporting electrolyte to the range of 3-5 mol / L provides sufficiently high ionic conductivity to the electrolyte without causing excessively high electrolyte viscosity that could hinder ion transport.

[0013] Preferably, the supporting electrolyte includes one or more of potassium chloride (KCl), sodium chloride (NaCl), lithium chloride (LiCl), potassium hydroxide (KOH), sodium hydroxide (NaOH), and lithium hydroxide (LiOH).

[0014] Beneficial Effects: The preferred supporting electrolyte of this invention possesses both excellent intrinsic chemical stability and electrochemical compatibility, enabling it to form a highly synergistic electrolyte system with the aforementioned zinc active material and multifunctional additives. Potassium hydroxide, sodium hydroxide, and lithium hydroxide, as alkaline supporting electrolytes, provide a strongly alkaline solution environment. The hydroxide ions generated by their dissociation have high ion migration rates, providing a high ionic conductivity for the electrolyte system. Potassium chloride, sodium chloride, and lithium chloride, as neutral supporting electrolytes, do not decompose or participate in reactions in a strongly alkaline environment, thus also improving the ionic conductivity of the electrolyte system.

[0015] This invention utilizes a combination of alkali metal hydroxides and chlorides as supporting electrolytes, unlike existing technologies that often use a single substance as the supporting electrolyte. This invention reduces ohmic polarization of the battery while maintaining the ionic conductivity of the electrolyte, ensuring stable battery operation. By flexibly adjusting the ratio of different supporting electrolytes, the viscosity, ion concentration, and pH value of the electrolyte can be controlled, enabling customized optimization of electrolyte performance for different application scenarios. This makes the invention applicable to various alkaline zinc-based flow battery systems, providing strong support for their large-scale promotion in energy storage, backup power, and other application scenarios.

[0016] Preferably, the solvent of the alkaline zinc-based flow battery electrolyte is deionized water.

[0017] A method for preparing an alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy includes the following steps: First, the zinc active material and additives are added to a solvent and mixed evenly. Then, a supporting electrolyte is added to the solution and the volume is adjusted to obtain the alkaline zinc-based flow battery electrolyte.

[0018] Beneficial Effects: This invention uses deionized water as the electrolyte solvent and employs a simplified preparation process, demonstrating significant industrial application value. It can form a highly compatible electrolyte system with the aforementioned preferred zinc active materials, multifunctional additives, and supporting electrolytes. Deionized water, as a solvent, has the advantages of being non-flammable, non-toxic, and inexpensive, fundamentally avoiding the problems of flammability, explosiveness, environmental pollution, and high cost associated with organic solvent systems. This results in an inherently safe electrolyte system, significantly reducing the raw material costs and subsequent waste disposal costs of the electrolyte. Simultaneously, deionized water can fully dissolve the various zinc active materials, multifunctional additives, and supporting electrolytes selected in this invention, ensuring the uniform dispersion and stable coexistence of all components in the electrolyte. This invention employs a preparation process that first coordinates the zinc active materials with the additives, followed by pH adjustment of the solution. This eliminates the need for heating, inert gas protection, or complex post-processing steps, simplifying the production process, reducing equipment investment and energy consumption, and improving the electrolyte production efficiency for large-scale applications of alkaline zinc-based flow batteries, thereby reducing the construction and maintenance costs of energy storage systems. Existing technologies use organic solvents in some electrolyte systems, which have drawbacks such as high safety risks, high cost, and poor environmental friendliness. In addition, some complex preparation processes have problems such as low production efficiency, high energy consumption, and poor product consistency between different batches. This invention overcomes the above technical difficulties, and achieves a balance between safety, economy, and product consistency during large-scale production while ensuring that the electrolyte has excellent electrochemical performance. This provides a technical path for the commercial application of alkaline zinc-based flow batteries in the field of large-scale long-term energy storage.

[0019] Application of an alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy in the anode electrolyte of an alkaline zinc-based flow battery.

[0020] Beneficial effects: This invention applies the alkaline zinc-based flow battery electrolyte designed based on the zinc anode interface regulation strategy to the anode side of the battery, which can fundamentally solve the core technical bottleneck of poor zinc anode interface stability that has long been faced in the industrialization process of alkaline zinc-based flow batteries.

[0021] The negative electrode electrolyte proposed in this invention integrates a selected range of zinc active materials and concentrations, a multi-electrolyte supporting system, multifunctional additives, and a deionized water solvent. These components form an organic whole, rather than a simple physical mixture. The multifunctional additives, through their unique oxygen, nitrogen, and phosphorus coordination atoms, form a stable coordination structure with the zinc active materials, while simultaneously forming an interfacial protective layer on the zinc negative electrode surface. The multi-electrolyte supporting system provides a solution environment with high ionic conductivity, and the optimized concentration parameters achieve a balance between the theoretical capacity of the electrolyte and its long-term operational stability. By applying this electrolyte to the negative electrode side, this invention enables multi-dimensional and multi-level synergistic regulation of the zinc negative electrode interface. By regulating the solvation structure of the zinc active materials, a uniform and dense zinc deposition layer can be induced; by reconstructing the hydrogen bond network in the solution through additive molecules, the hydrogen evolution reaction can be suppressed; and by the specific adsorption of the additives on the zinc negative electrode surface, direct contact between the zinc active materials and the electrolyte can be prevented, effectively inhibiting irreversible capacity loss caused by zinc self-corrosion. The synergistic effect of the above mechanisms can systematically improve the interfacial reaction environment of the zinc anode, solve the core problems of uneven zinc deposition, severe hydrogen evolution and self-corrosion in traditional electrolytes, significantly improve the interfacial stability and electrochemical reaction reversibility of the zinc anode during long-term cycling, effectively improve the coulombic efficiency and energy efficiency of alkaline zinc-based flow batteries, greatly extend the stable cycle life of the battery, and improve the overall operational safety and reliability of the battery system.

[0022] Existing technologies often improve interface stability through complex methods such as anode surface modification and separator structure design, which suffer from drawbacks such as cumbersome processes, high costs, and poor compatibility with existing battery systems. This invention achieves a comprehensive improvement in zinc anode interface stability solely through electrolyte optimization, without requiring any changes to the battery structure, electrode fabrication process, or production flow. It boasts significant advantages such as simple process, low cost, and ease of large-scale scalability. This application provides an efficient, economical, and feasible technical solution to the problem of poor zinc anode interface stability in alkaline zinc-based flow batteries, and can strongly promote its commercial application in large-scale long-term energy storage, grid peak shaving, and backup power.

[0023] Preferably, the alkaline zinc-based flow battery includes one of the following: zinc-iron battery, zinc-iodine battery, zinc-sulfur battery, zinc-bromine battery, zinc-manganese battery, zinc-nickel battery, and zinc-air battery.

[0024] Beneficial Effects: The alkaline zinc-based flow battery electrolyte proposed in this invention has universality and is not limited to a single specific system. It can be widely adapted to various alkaline zinc-based flow battery systems, such as zinc-iron, zinc-iodine, zinc-sulfur, zinc-bromine, zinc-manganese, zinc-nickel, and zinc-air. Its core advantage lies in the fact that the design logic of this electrolyte is not customized for a specific system, but rather focuses on the common technical bottleneck of poor zinc anode interface stability faced by all alkaline zinc-based flow batteries. It systematically solves the three major problems of uneven zinc deposition, hydrogen evolution, and self-corrosion side reactions. Therefore, this electrolyte can be directly applied without significant formulation adjustments for different cathode systems. This significantly shortens the R&D cycle for different zinc-based flow battery systems, reduces the R&D and production costs of electrolyte formulations, and avoids the redundant investment of R&D resources and industrialization barriers caused by the "one system, one formulation" model in existing technologies.

[0025] Meanwhile, this electrolyte maintains stable and efficient interface regulation in all the aforementioned alkaline zinc-based flow battery systems, generally improving the coulombic efficiency, energy efficiency, rate performance, and long-cycle stability of different battery systems. It effectively solves the problem of rapid performance degradation and limited cycle life caused by negative electrode interface deterioration in different systems. By flexibly adjusting the proportions of each component in the electrolyte, performance can be further customized and optimized for different systems' operating voltage, current density, and application scenarios, achieving precise matching of electrolyte performance with the specific battery system requirements.

[0026] This invention improves the stability of the negative electrode interface in alkaline zinc-based flow batteries by focusing on a universal electrolyte design that addresses common problems. This not only provides a universal technical solution for improving the performance of various alkaline zinc-based flow batteries, but also greatly expands the application scope and market potential of this invention, promoting the large-scale commercialization of alkaline zinc-based flow battery energy storage technology.

[0027] An alkaline zinc-based flow battery includes a positive electrode, a negative electrode, a positive electrolyte, a negative electrolyte, and a battery separator, wherein the negative electrolyte is the alkaline zinc-based flow battery electrolyte described above.

[0028] Beneficial Effects: The alkaline zinc-based flow battery provided by this invention achieves a high degree of compatibility between the battery's positive and negative electrodes, separator, and electrolyte system. This battery integrates the core advantages of the negative electrode electrolyte. Specifically, the selected zinc active material and supporting electrolyte system provide a high-capacity and low-ohmic-polarization ion conduction environment; the multifunctional additive system systematically solves the three common problems of uneven zinc deposition, hydrogen evolution, and self-corrosion; and the deionized aqueous solvent and simple preparation process endow the electrolyte with inherent safety, low cost, and ease of large-scale production. Furthermore, the electrolyte proposed in this invention exhibits excellent compatibility with various mainstream positive and negative electrode materials and commercial battery separators, ensuring long-term safe and stable battery operation.

[0029] Unlike existing technologies where alkaline zinc-based flow batteries often rely on complex electrode surface modifications and membrane structure designs—methods that are cumbersome, costly, and incompatible with existing industrial production systems—this invention achieves a comprehensive improvement in battery performance simply by optimizing the negative electrode electrolyte formulation. It requires no modifications to the electrodes, current collectors, separators, or production processes, offering significant advantages such as ease of implementation and rapid industrialization. This invention provides a low-cost, highly safe, and long-life energy storage solution for large-scale, long-duration energy storage, grid peak shaving, and industrial / commercial backup power, significantly advancing the commercial application of alkaline zinc-based flow batteries.

[0030] Preferably, the battery separator comprises one or more of perfluorosulfonic acid proton exchange membranes, sulfonated polyether ether ketone membranes, and polybenzimidazole membranes.

[0031] Beneficial Effects: The preferred battery separator types of this invention possess both excellent intrinsic electrochemical performance and adaptability to strongly alkaline environments, making them highly compatible with the aforementioned negative electrode electrolytes based on zinc negative electrode interface control strategies and various positive electrode systems. Specifically, the perfluorosulfonic acid proton exchange membrane exhibits superior chemical stability, resisting molecular chain breakage and performance degradation in strongly alkaline electrolytes and during long-term charge-discharge cycles; the sulfonated polyetheretherketone membrane possesses high hydroxide ion conductivity and good mechanical toughness, and its raw material cost is significantly lower than that of the perfluorosulfonic acid membrane, offering both performance and economic advantages; and the polybenzimidazole membrane exhibits excellent high-temperature resistance and anti-swelling ability, maintaining structural integrity and ion conductivity under extreme temperature conditions. All three types effectively block the transmembrane migration of large-sized zinc active material and organic additive molecules while allowing efficient carrier passage.

[0032] By selecting the aforementioned high-performance separator, this invention can ensure efficient ion conduction inside the battery and reduce ohmic polarization while blocking the cross-migration of zinc active materials and suppressing battery self-discharge. Its excellent chemical stability ensures that the separator can operate stably in a strongly alkaline electrolyte for a long time without the loss of ion conduction performance or mechanical strength due to corrosion degradation. Its high mechanical strength and puncture resistance can effectively resist the puncture damage of tiny dendrites that may be generated on the surface of the zinc negative electrode, preventing battery short-circuit failure.

[0033] Unlike some existing alkaline zinc-based flow batteries that use ordinary porous membranes or traditional anion exchange membranes, which have inherent defects such as high zinc ion permeability, poor alkalinity stability, and insufficient mechanical strength, leading to severe self-discharge, short cycle life, and internal short circuit risk, the membrane system preferred in this invention combines high ion selectivity, excellent chemical stability, and reliable mechanical properties. It achieves deep performance compatibility with the negative electrode electrolyte proposed in this invention, jointly constructing a highly stable and long-life alkaline zinc-based flow battery system, providing a solid guarantee for the long-term reliable operation of the battery.

[0034] Compared with the prior art, the present invention has the following advantages and technical effects: This invention introduces a multifunctional electrolyte additive with zinc anode interface regulation function into the traditional negative electrode electrolyte of an alkaline zinc-based flow battery. Through the coordination interaction between the additive molecules and the zinc active material, the solvation structure of the zinc active material is reconstructed, slowing down the zinc deposition reaction kinetics, balancing the rate difference between active material transport and deposition reaction kinetics, promoting zinc deposition with a uniform morphology, and inhibiting the formation of zinc dendrites. Simultaneously, the additive in this invention participates in reconstructing the hydrogen bond network in the solution, reducing the content of easily reduced highly reactive water molecules in the solution, and inhibiting hydrogen evolution side reactions. Furthermore, the additive in this invention can specifically adsorb the zinc elemental surface deposited on the electrode, constructing a dense interfacial protective layer, hindering the attack of corrosive media on zinc in the solution, and thus inhibiting self-corrosion side reactions. Based on the comprehensive effect of the above-mentioned interface regulation function, the alkaline zinc-based flow battery electrolyte obtained by this invention can significantly improve the energy efficiency and cycle stability of alkaline zinc-based flow batteries. Moreover, the method provided by this invention uses readily available raw materials, is simple to prepare, and is easy to promote and apply. Attached Figure Description

[0035] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the structure of the alkaline zinc-iron flow battery in an embodiment of the present invention; The components are labeled as follows: battery separator 1, positive electrode 2, negative electrode 3, positive electrode flow field plate 4, negative electrode flow field plate 5, positive electrode current collector 6, negative electrode current collector 7, positive electrode end plate 8, negative electrode end plate 9, positive electrode peristaltic pump 10, negative electrode peristaltic pump 11, positive electrode liquid storage tank 12, and negative electrode liquid storage tank 13. Figure 2 This is a SEM scan of the microstructure of zinc deposition in the alkaline zinc-iron flow battery obtained in Comparative Application Example 1 of the present invention. Among them, (a) represents a zinc deposition area capacity of 10 mAh / cm². 2The microstructure at time (b) shows the zinc deposition area capacity of 20 mAh / cm². 2 The microstructure at that time, (c) shows the zinc deposition area capacity of 30 mAh / cm². 2 The microstructure at time (d) shows the zinc deposition area capacity of 40 mAh / cm². 2 Microscopic morphology at that time; Figure 3 This is a SEM scan of the microstructure of zinc deposition in the alkaline zinc-iron flow battery obtained in Example 1 of this invention. Where (a) is the zinc deposition area capacity of 10 mAh / cm². 2 The microstructure at time (b) shows the zinc deposition area capacity of 20 mAh / cm². 2 The microstructure at that time, (c) shows the zinc deposition area capacity of 30 mAh / cm². 2 The microstructure at time (d) shows the zinc deposition area capacity of 40 mAh / cm². 2 Microscopic morphology at time; Figure 4 The graph shows the hydrogen evolution overpotential and hydrogen evolution current density of the negative electrode electrolyte in the alkaline zinc-iron flow battery obtained in Application Example 1 and Comparative Application Example 1 of the present invention. Figure 5 The images show the surface microstructure of high-purity zinc sheets after being immersed for 5 days in the alkaline zinc-based flow battery electrolyte obtained in Example 1 and the negative electrode electrolyte obtained in Comparative Example 1, respectively. Among them, (a) is the microstructure of the zinc sheet used in Comparative Example 1 before immersion, (b) is the microstructure of the zinc sheet used in Comparative Example 1 after immersion for 5 days, (c) is the microstructure of the zinc sheet used in Example 1 before immersion, and (d) is the microstructure of the zinc sheet used in Example 1 after immersion for 5 days. Figure 6 The graph shows the charge and discharge test results of the alkaline zinc-based flow battery obtained in Example 1 of this invention. Figure 7 The graph shows the long-cycle test results of the alkaline zinc-based flow battery obtained in Application Example 1 of this invention; Figure 8 The graph shows the charge-discharge test results of the alkaline zinc-based flow battery obtained in Comparative Application Example 1 of this invention. Figure 9 The graph shows the long-cycle test results of the alkaline zinc-based flow battery obtained in Comparative Application Example 1 of this invention. Figure 10 The graph shows the charge-discharge test results of the alkaline zinc-based flow battery obtained in Comparative Application Example 2 of this invention. Figure 11 The graph shows the charge-discharge test results of the alkaline zinc-based flow battery obtained in Comparative Application Example 3 of this invention. Figure 12The graph shows the charge-discharge test results of the alkaline zinc-based flow battery obtained in Comparative Application Example 4 of this invention. Detailed Implementation

[0036] 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.

[0037] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] Unless otherwise specified, all raw materials used in the embodiments of this invention were purchased through commercial channels; Unless otherwise specified, room temperature or normal temperature in the embodiments of the present invention refers to 25±3℃.

[0039] Example 1 An alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy, wherein the solvent is water and the electrolyte comprises raw materials of the following concentrations: Active substance (zinc chloride 0.2 mol / L), additive (diethylenetriaminepentaacetic acid 0.1 mol / L), supporting electrolyte (sodium hydroxide 1.6 mol / L, potassium hydroxide 1.4 mol / L and lithium hydroxide 0.5 mol / L); A method for preparing an alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy, using the raw materials described in this embodiment, includes the following steps: Dissolve 0.5452 g zinc chloride and 0.7867 g diethylenetriaminepentaacetic acid in deionized water, then add 1.2800 g sodium hydroxide, 1.5711 g potassium hydroxide and 0.2395 g lithium hydroxide and stir to dissolve. Then transfer to a 20 mL volumetric flask and make up to volume to obtain the alkaline zinc-based flow battery electrolyte.

[0040] Application Example 1 An alkaline zinc-iron flow battery, such as Figure 1 As shown, the battery includes: a battery separator 1, a positive electrode 2, a negative electrode 3, a positive flow field plate 4, a negative flow field plate 5, a positive current collector 6, a negative current collector 7, a positive terminal plate 8, a negative terminal plate 9, a positive peristaltic pump 10, a negative peristaltic pump 11, a positive electrolyte reservoir 12, and a negative electrolyte reservoir 13. An external power source or load is connected to the alkaline zinc-iron flow battery through the positive current collector 6 and the negative current collector 7; the positive terminal plate 8 and the negative terminal plate 9 are used to fix the alkaline zinc-iron flow battery. According to... Figure 1The structural diagram shows the assembly of the battery components, resulting in an alkaline zinc-iron flow battery.

[0041] Both the positive electrode 2 and the negative electrode 3 are made of graphite felt, with an electrode area of ​​2 × 2.5 cm. 2 ; Battery separator 1 is a Nafion 212 membrane with an area of ​​4 × 5 cm. 2 ; The negative electrode storage tank 13 contains a negative electrode electrolyte, which is the alkaline zinc-based flow battery electrolyte obtained in Example 1; The positive electrode storage tank 12 contains a positive electrode electrolyte, the solvent of which is water, and the electrolyte comprises raw materials of the following concentrations: Active substance (sodium ferrocyanide 0.4 mol / L), supporting electrolyte (potassium hydroxide 1.4 mol / L and lithium hydroxide 0.5 mol / L); The preparation method of the positive electrode electrolyte includes the following steps: Dissolve 2.4313 g sodium ferrocyanide, 1.5711 g potassium hydroxide, and 0.2395 g lithium hydroxide in deionized water, then transfer the solution to a 20 mL volumetric flask and bring it to a final volume to obtain the positive electrode electrolyte.

[0042] The working principle of an alkaline zinc-iron flow battery is as follows: The positive electrolyte in the positive electrode storage tank 12 enters the positive electrode flow field plate 4 through the positive electrode peristaltic pump 10. The positive electrode 2 is fixed on the positive electrode flow field plate 4. The active substances 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 electrode storage tank 12. The negative electrode electrolyte in the negative electrode storage tank 13 enters the negative electrode flow field plate 5 through the negative electrode peristaltic pump 11. The negative electrode 3 is fixed on the negative electrode flow field plate 5. The active substances in the negative electrode electrolyte will undergo an electrochemical reaction on the surface of the negative electrode 3. After that, the negative electrode electrolyte flows out of the negative electrode 3 and re-enters the negative electrode storage tank 13.

[0043] Because of the presence of the battery separator 1, the positive electrolyte on the surface of the positive electrode 2 and the negative electrolyte on the surface of the negative electrode 3 are independent of each other, and only charge carriers can pass through the separator.

[0044] Example 2 An alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy, wherein the solvent is water and the electrolyte comprises raw materials of the following concentrations: Active substance (zinc chloride 0.4 mol / L), additive (hydroxyethylidene diphosphate 0.4 mol / L), supporting electrolyte (sodium hydroxide 0.5 mol / L, potassium hydroxide 3.2 mol / L and lithium hydroxide 0.5 mol / L); A method for preparing an alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy, using the raw materials described in this embodiment, includes the following steps: Dissolve 1.0904 g zinc chloride and 1.6482 g hydroxyethylidene diphosphate in deionized water. Then add 0.4000 g sodium hydroxide, 3.5910 g potassium hydroxide, and 0.2395 g lithium hydroxide. Stir to dissolve, then transfer to a 20 mL volumetric flask and make up to volume to obtain the alkaline zinc-based flow battery electrolyte.

[0045] Application Example 2 An alkaline zinc-iron flow battery differs from Application Example 1 only in that both the positive and negative electrodes are made of graphite felt, with an electrode area of ​​2 × 2.5 cm². 2 ; The battery separator is a sulfonated polyetheretherketone separator with an area of ​​4×5 cm. 2 ; The negative electrode electrolyte is the alkaline zinc-based flow battery electrolyte obtained in Example 2; The solvent for the positive electrode electrolyte is water, and the electrolyte comprises raw materials of the following concentrations: Active substance (potassium ferrocyanide 0.8 mol / L), supporting electrolyte (sodium hydroxide 0.5 mol / L and lithium hydroxide 0.5 mol / L); The preparation method of the positive electrode electrolyte includes the following steps: Dissolve 5.8942 g sodium ferrocyanide, 0.4000 g sodium hydroxide, and 0.2395 g lithium hydroxide in deionized water, then transfer the solution to a 20 mL volumetric flask and bring it to a final volume to obtain the positive electrode electrolyte.

[0046] Other structures, connection methods, and working principles are the same as in Application Example 1.

[0047] Example 3 An alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy, wherein the solvent is water and the electrolyte comprises raw materials of the following concentrations: Active substance (zinc chloride 0.2 mol / L), additive (diethylenetriaminepentamethylene phosphoric acid 0.1 mol / L), supporting electrolyte (sodium hydroxide 1.6 mol / L, potassium hydroxide 1.4 mol / L and lithium hydroxide 0.5 mol / L); A method for preparing an alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy, using the raw materials described in this embodiment, includes the following steps: Dissolve 0.5452 g zinc chloride and 0.1146 g diethylenetriaminepentamethylene phosphoric acid in deionized water, then add 1.2800 g sodium hydroxide, 1.5711 g potassium hydroxide and 0.2395 g lithium hydroxide and stir to dissolve. Then transfer to a 20 mL volumetric flask and make up to volume to obtain the alkaline zinc-based flow battery electrolyte.

[0048] Application Example 3 An alkaline zinc-iron flow battery differs from Application Example 1 only in that both the positive and negative electrodes are made of graphite felt, with an electrode area of ​​2 × 2.5 cm². 2 ; The battery separator is a Nafion 211 membrane with an area of ​​4 × 5 cm. 2 ; The negative electrode electrolyte is the alkaline zinc-based flow battery electrolyte obtained in Example 3; The solvent for the positive electrode electrolyte is water, and the electrolyte comprises raw materials of the following concentrations: Active substance (sodium ferrocyanide 0.4 mol / L), supporting electrolyte (potassium hydroxide 1.0 mol / L, lithium hydroxide 0.5 mol / L and potassium chloride 0.4 mol / L); The preparation method of the positive electrode electrolyte includes the following steps: Dissolve 2.4313 g sodium ferrocyanide, 1.1222 g potassium hydroxide, 0.2395 g lithium hydroxide, and 0.5964 g potassium chloride in deionized water, then transfer the solution to a 20 mL volumetric flask and dilute to volume to obtain the positive electrode electrolyte.

[0049] Other structures, connection methods, and working principles are the same as in Application Example 1.

[0050] Example 4 An alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy, wherein the solvent is water and the electrolyte comprises raw materials of the following concentrations: Active substance (zinc chloride 0.1 mol / L), additive (sodium heptahydrate 0.1 mol / L), supporting electrolyte (sodium hydroxide 0.7 mol / L, potassium hydroxide 2 mol / L and lithium hydroxide 0.5 mol / L); A method for preparing an alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy, using the raw materials described in this embodiment, includes the following steps: Dissolve 0.2726 g zinc chloride and 0.4323 g sodium heptadate in deionized water, then add 0.5600 g sodium hydroxide, 2.2444 g potassium hydroxide and 0.2395 g lithium hydroxide and stir to dissolve. Then transfer to a 20 mL volumetric flask and make up to volume to obtain the alkaline zinc-based flow battery electrolyte.

[0051] Application Example 4 An alkaline zinc-iron flow battery differs from Application Example 1 only in that both the positive and negative electrodes are made of graphite felt, with an electrode area of ​​2 × 2.5 cm². 2 ; The battery separator is a Nafion 117 membrane with an area of ​​4 × 5 cm. 2 ; The negative electrode electrolyte is the alkaline zinc-based flow battery electrolyte obtained in Example 4; The solvent for the positive electrode electrolyte is water, and the electrolyte comprises raw materials of the following concentrations: Active substance (sodium ferrocyanide 0.2 mol / L), supporting electrolyte (potassium hydroxide 1.0 mol / L, lithium hydroxide 0.5 mol / L and sodium chloride 1.0 mol / L); The preparation method of the positive electrode electrolyte includes the following steps: Dissolve 1.2156 g sodium ferrocyanide, 1.1222 g potassium hydroxide, 0.2395 g lithium hydroxide and 1.0688 g sodium chloride in deionized water, then transfer the solution to a 20 mL volumetric flask and bring it to a final volume to obtain the positive electrode electrolyte.

[0052] Other structures, connection methods, and working principles are the same as in Application Example 1.

[0053] Example 5 An alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy, wherein the solvent is water and the electrolyte comprises raw materials of the following concentrations: Active substance (zinc chloride 0.2 mol / L), additive (aminotriacetic acid 0.4 mol / L), supporting electrolyte (sodium hydroxide 1.6 mol / L, potassium hydroxide 1.4 mol / L and lithium hydroxide 0.5 mol / L); A method for preparing an alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy, using the raw materials described in this embodiment, includes the following steps: Dissolve 0.5452 g zinc chloride and 1.5291 g aminotriacetic acid in deionized water, then add 1.2800 g sodium hydroxide, 1.5711 g potassium hydroxide and 0.2395 g lithium hydroxide and stir to dissolve. Then transfer to a 20 mL volumetric flask and make up to volume to obtain the alkaline zinc-based flow battery electrolyte.

[0054] Application Example 5 An alkaline zinc-iron flow battery differs from Application Example 1 only in that both the positive and negative electrodes are made of graphite felt, with an electrode area of ​​2 × 2.5 cm². 2 ; The battery separator is a Nafion 115 membrane with an area of ​​4 × 5 cm. 2 ; The negative electrode electrolyte is the alkaline zinc-based flow battery electrolyte obtained in Example 5; The solvent for the positive electrode electrolyte is water, and the electrolyte comprises raw materials of the following concentrations: Active substance (sodium ferrocyanide 0.4 mol / L), supporting electrolyte (potassium hydroxide 1.4 mol / L and lithium hydroxide 0.5 mol / L); The preparation method of the positive electrode electrolyte includes the following steps: Dissolve 2.4313 g sodium ferrocyanide, 1.5711 g potassium hydroxide, and 0.2395 g lithium hydroxide in deionized water, then transfer the solution to a 20 mL volumetric flask and bring it to a final volume to obtain the positive electrode electrolyte.

[0055] Other structures, connection methods, and working principles are the same as in Application Example 1.

[0056] Example 6 An alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy, wherein the solvent is water and the electrolyte comprises raw materials of the following concentrations: Active substance (zinc chloride 1.5 mol / L), additive (bis(2-hydroxyethyl)amino(tris(hydroxymethyl)methane) 1.5 mol / L), supporting electrolyte (potassium hydroxide 4 mol / L); A method for preparing an alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy, using the raw materials described in this embodiment, includes the following steps: 4.0890 g of zinc chloride and 6.2772 g of bis(2-hydroxyethyl)amino(tris(hydroxymethyl)methane) were dissolved in deionized water. Then, 4.4888 g of potassium hydroxide was added and stirred until dissolved. The solution was then transferred to a 20 mL volumetric flask and brought to a final volume to obtain the alkaline zinc-based flow battery electrolyte.

[0057] Application Example 6 An alkaline zinc-iodine flow battery differs from Application Example 1 only in that both the positive and negative electrodes are made of graphite felt, with an electrode area of ​​2 × 2.5 cm². 2 ; The battery separator is a Nafion 115 membrane with an area of ​​4 × 5 cm. 2 ; The negative electrode electrolyte is the alkaline zinc-based flow battery electrolyte obtained in Example 6; The solvent for the positive electrode electrolyte is water, and the electrolyte comprises raw materials of the following concentrations: Active substance (potassium iodide 2 mol / L), supporting electrolyte (potassium chloride 2 mol / L); The preparation method of the positive electrode electrolyte includes the following steps: Dissolve 6.6400 g of potassium iodide and 2.2365 g of potassium chloride in deionized water, then transfer the solution to a 20 mL volumetric flask and bring it to a final volume to obtain the positive electrode electrolyte.

[0058] Other structures, connection methods, and working principles are the same as in Application Example 1.

[0059] Example 7 An alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy, wherein the solvent is water and the electrolyte comprises raw materials of the following concentrations: Active substance (zinc chloride 0.1 mol / L), additive (ethylenediaminetetramethylene phosphoric acid 0.1 mol / L), supporting electrolyte (potassium hydroxide 2.5 mol / L and lithium hydroxide 0.5 mol / L); A method for preparing an alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy, using the raw materials described in this embodiment, includes the following steps: Dissolve 0.2726 g zinc chloride and 0.8722 g ethylenediaminetetramethylene phosphoric acid in deionized water, then add 2.8055 g potassium hydroxide and 0.2395 g lithium hydroxide and stir to dissolve. Transfer the solution to a 20 mL volumetric flask and bring it to a final volume to obtain the alkaline zinc-based flow battery electrolyte.

[0060] Application Example 7 An alkaline zinc-sulfur flow battery differs from Application Example 1 only in that both the positive and negative electrodes are made of graphite felt, with an electrode area of ​​2 × 2.5 cm². 2 ; The battery separator is a Nafion 115 membrane with an area of ​​4 × 5 cm. 2 ; The negative electrode electrolyte is the alkaline zinc-based flow battery electrolyte obtained in Example 7; The solvent for the positive electrode electrolyte is water, and the electrolyte comprises raw materials of the following concentrations: Active material (potassium sulfide 1 mol / L), supporting electrolyte (potassium hydroxide 2.5 mol / L and lithium hydroxide 0.5 mol / L); The preparation method of the positive electrode electrolyte includes the following steps: Dissolve 2.2052 g potassium sulfide, 2.8055 g potassium hydroxide, and 0.2395 g lithium hydroxide in deionized water, then transfer the solution to a 20 mL volumetric flask and bring it to a final volume to obtain the positive electrode electrolyte.

[0061] Other structures, connection methods, and working principles are the same as in Application Example 1.

[0062] Comparative Example 1 An alkaline zinc-based flow battery negative electrode electrolyte, using water as the solvent, differs from Example 1 only in that the electrolyte does not contain additives, and specifically includes the following raw materials at the following concentrations: Active substance (zinc chloride 0.2 mol / L), supporting electrolyte (sodium hydroxide 1.6 mol / L, potassium hydroxide 1.4 mol / L and lithium hydroxide 0.5 mol / L); A method for preparing an alkaline zinc-based flow battery negative electrode electrolyte, using the raw materials described in this comparative example, includes the following steps: 0.5452 g zinc chloride, 1.2800 g sodium hydroxide, 1.5711 g potassium hydroxide, and 0.2395 g lithium hydroxide were added to deionized water and stirred to dissolve. The solution was then transferred to a 20 mL volumetric flask and diluted to volume to obtain the alkaline zinc-based flow battery negative electrode electrolyte.

[0063] Comparative Application Example 1 An alkaline zinc-iron flow battery differs from Application Example 1 only in that both the positive and negative electrodes are made of graphite felt, with an electrode area of ​​2 × 2.5 cm². 2 ; The battery separator is a Nafion 212 membrane with an area of ​​4 × 5 cm. 2 ; The negative electrode electrolyte is the alkaline zinc-based flow battery electrolyte obtained in Comparative Example 1; The solvent for the positive electrode electrolyte is water, and the electrolyte comprises raw materials of the following concentrations: Active substance (sodium ferrocyanide 0.4 mol / L), supporting electrolyte (potassium hydroxide 1.4 mol / L and lithium hydroxide 0.5 mol / L); The preparation method of the positive electrode electrolyte includes the following steps: Dissolve 2.4313 g sodium ferrocyanide, 1.5711 g potassium hydroxide, and 0.2395 g lithium hydroxide in deionized water, then transfer the solution to a 20 mL volumetric flask and bring it to a final volume to obtain the positive electrode electrolyte.

[0064] Other structures, connection methods, and working principles are the same as in Application Example 1.

[0065] Comparative Example 2 An alkaline zinc-based flow battery negative electrode electrolyte, using water as the solvent, differs from Example 1 only in that the additive concentration in the electrolyte is 0.4 mol / L, specifically including the following raw materials at the following concentrations: Active substance (zinc chloride 0.2 mol / L), additive (diethylenetriaminepentaacetic acid 0.4 mol / L), supporting electrolyte (sodium hydroxide 1.6 mol / L, potassium hydroxide 1.4 mol / L and lithium hydroxide 0.5 mol / L); A method for preparing an alkaline zinc-based flow battery negative electrode electrolyte, using the raw materials described above in this comparative example, with the remaining process steps being the same as in Example 1.

[0066] Comparative Application Example 2 An alkaline zinc-iron flow battery differs from Application Example 1 only in that the negative electrode electrolyte is the alkaline zinc-based flow battery electrolyte obtained in Comparative Example 2; the other structures, connection methods, and working principles are the same as in Application Example 1.

[0067] Comparative Example 3 An alkaline zinc-based flow battery negative electrode electrolyte, using water as the solvent, differs from Example 1 only in that the active material zinc chloride is replaced with zinc oxide of the same concentration; the remaining raw materials and their amounts are the same as in Example 1, specifically including the following concentrations of raw materials: Active material (zinc oxide 0.2 mol / L), additive (diethylenetriaminepentaacetic acid 0.1 mol / L), supporting electrolyte (sodium hydroxide 1.6 mol / L, potassium hydroxide 1.4 mol / L and lithium hydroxide 0.5 mol / L); A method for preparing an alkaline zinc-based flow battery negative electrode electrolyte, using the raw materials described above in this comparative example, with the remaining process steps being the same as in Example 1.

[0068] Comparative Application Example 3 An alkaline zinc-iron flow battery differs from Application Example 1 only in that the negative electrode electrolyte is the alkaline zinc-based flow battery electrolyte obtained in Comparative Example 3; the other structures, connection methods, and working principles are the same as in Application Example 1.

[0069] Comparative Example 4 An alkaline zinc-based flow battery negative electrode electrolyte, using water as the solvent, differs from Example 1 only in that the electrolyte can be replaced with sodium hydroxide 3 mol / L and lithium hydroxide 0.5 mol / L. The remaining raw materials and their amounts are the same as in Example 1, specifically including the following concentrations of raw materials: Active substance (zinc chloride 0.2 mol / L), additive (diethylenetriaminepentaacetic acid 0.1 mol / L), supporting electrolyte (sodium hydroxide 3 mol / L, lithium hydroxide 0.5 mol / L); A method for preparing an alkaline zinc-based flow battery negative electrode electrolyte, using the raw materials described above in this comparative example, with the remaining process steps being the same as in Example 1.

[0070] Comparative Application Example 4 An alkaline zinc-iron flow battery differs from Application Example 1 only in that the negative electrode electrolyte is the alkaline zinc-based flow battery electrolyte obtained in Comparative Example 4; the other structures, connection methods, and working principles are the same as in Application Example 1.

[0071] Technical effects: 1. Evaluation of the role of zinc deposition morphology Using the alkaline zinc-iron flow battery of Application Example 1 and Comparative Application Example 1, 10~40 mAh / cm³ was deposited on the graphite felt electrode. 2 The microstructure of zinc deposits was observed using scanning electron microscopy (SEM) to measure the area of ​​zinc.

[0072] Figure 2 The SEM scan image shows the microstructure of zinc deposition in the alkaline zinc-iron flow battery obtained in Comparative Application Example 1 of this invention. It can be seen that when the negative electrode electrolyte described in the comparative example is used, zinc is deposited on the electrode in a loose morphology with moss-like dendrites. Figure 3 The image shows a SEM scan of the microstructure of zinc deposition in the alkaline zinc-iron flow battery obtained in Example 1 of this invention. It can be seen that when the negative electrode electrolyte described in Example 1 is used, zinc is deposited on the electrode in a uniform and dense morphology, exhibiting a regular crystal structure.

[0073] 2. Performance evaluation of inhibiting hydrogen evolution reaction The hydrogen evolution overpotential and hydrogen evolution current density of the negative electrode electrolyte described in Example 1 and the comparative example were tested using linear sweep voltammetry (LSV). The LSV tests were performed in a three-electrode system, where the working electrode was the same graphite felt electrode as in Application Example 1; the counter electrode was a graphite rod electrode; and the reference electrode was a Hg / HgO electrode. The test results are as follows: Figure 4 As shown.

[0074] Depend on Figure 4 It can be seen that the hydrogen evolution overpotential and hydrogen evolution current density of the negative electrode electrolyte in Example 1 are both reduced, indicating that the hydrogen evolution side reaction is suppressed.

[0075] 3. Evaluation of performance in inhibiting self-corrosion reaction The effect of additives on inhibiting electrode self-corrosion reaction was evaluated using a zinc sheet immersion test, including the following steps: At room temperature, high-purity zinc sheets (purity > 99.99%) were immersed in the alkaline zinc-based flow battery electrolyte obtained in Example 1 and the negative electrode electrolyte obtained in Comparative Example 1 for 5 days, respectively. After that, the zinc sheets were taken out, rinsed with deionized water, and dried in a vacuum drying oven for 24 hours. The corrosion of the zinc sheets was observed under a scanning electron microscope.

[0076] The results are as follows Figure 5 As shown, the zinc sheet soaked in the negative electrode electrolyte obtained in Comparative Example 1 for 5 days has a rough microstructure, severe surface corrosion, and corrosion products. The zinc sheet soaked in the negative electrode electrolyte described in Example 1 for 5 days has a smooth microstructure and no corrosion products.

[0077] 4. Electrical properties To evaluate the rate performance of the alkaline zinc-iron flow battery in this invention, a battery with an area capacity of 20 mAh / cm² was used. 2 Under the experimental conditions, the alkaline zinc-iron flow batteries obtained in Application Example 1 and Comparative Application Example 1 were tested at 40 mA / cm². 2 Up to 100 mA / cm 2 Charge and discharge tests were conducted within the specified current density range.

[0078] The charge-discharge test results of the alkaline zinc-iron flow battery obtained in Example 1 are as follows: Figure 6 As shown, the battery operates at 40 mA / cm². 2 Up to 100 mA / cm 2 Within the current density range, it can maintain high coulombic efficiency, voltage efficiency and energy efficiency.

[0079] The charge-discharge test results of the alkaline zinc-iron flow battery obtained in Application Example 1 are as follows: Figure 8 As shown, the battery operates at 40 mA / cm². 2 Up to 100 mA / cm 2 Within the current density range, the coulombic efficiency, voltage efficiency, and energy efficiency are all relatively low.

[0080] The charge-discharge test results of the alkaline zinc-iron flow battery obtained in Application Example 2 are as follows: Figure 10 As shown, the battery operates at 40 mA / cm². 2 Up to 100 mA / cm 2 Within the current density range, the coulombic efficiency, voltage efficiency, and energy efficiency are all higher than those of Comparative Application Example 1, but lower than those of Application Example 1.

[0081] The charge-discharge test results of the alkaline zinc-iron flow battery obtained in Example 3 are as follows: Figure 11 As shown, the battery operates at 40 mA / cm². 2 Up to 100 mA / cm 2 Within the current density range, the coulombic efficiency, voltage efficiency, and energy efficiency are all higher than those of Comparative Application Example 1, but lower than those of Application Example 1.

[0082] The charge-discharge test results of the alkaline zinc-iron flow battery obtained in Example 4 are as follows: Figure 12 As shown, the battery operates at 40 mA / cm². 2 Up to 100 mA / cm 2 Within the current density range, the coulombic efficiency, voltage efficiency, and energy efficiency are all higher than those of Comparative Application Example 1, but lower than those of Application Example 1.

[0083] To evaluate the long-cycle performance of the alkaline zinc-iron flow battery of the present invention, the alkaline zinc-iron flow batteries obtained in Application Example 1 and Comparative Application Example 1 were compared at an areal capacity of 20 mAh / cm². 2 The current density is 80 mA / cm². 2 Long-cycle testing was conducted under the experimental conditions.

[0084] The long-cycle test results of the alkaline zinc-iron flow battery obtained in Example 1 are as follows: Figure 7 As shown in the figure, the battery can be seen to stably cycle 500 times under these conditions. This indicates that the battery has excellent cycle stability.

[0085] The long-cycle test results of the alkaline zinc-iron flow battery obtained in Application Example 1 are as follows: Figure 9 As shown, under these conditions, the battery can only cycle stably for about 170 cycles, after which the discharge capacity and discharge energy decrease significantly, indicating that the cycle stability of the alkaline zinc-iron flow battery using the conventional negative electrode electrolyte in Application Example 1 is poor.

[0086] The above are merely preferred embodiments 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. An alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy, characterized in that, Includes zinc active material, supporting electrolyte, and additives; The concentration of the additive is 0.01-1.5 mol / L; the additive includes one or more of sodium gluconate, sodium heptadate, triethanolamine, diethylenetriaminepentaacetic acid, bis(2-hydroxyethyl)amino(trihydroxymethyl)methane, aminotriacetic acid, hydroxyethylidene diphosphate, diethylenetriaminepentamethylene phosphate, and ethylenediaminetetramethylene phosphate.

2. The alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy according to claim 1, characterized in that, The concentration of the zinc active material is 0.1-1.5 mol / L; the concentration of the supporting electrolyte is 3-5 mol / L.

3. The alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy according to claim 2, characterized in that, The zinc active material includes one or more of zinc chloride, zinc bromide, and zinc oxide.

4. The alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy according to claim 2, characterized in that, The supporting electrolyte includes one or more of potassium chloride, sodium chloride, lithium chloride, potassium hydroxide, sodium hydroxide, and lithium hydroxide.

5. The alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy according to claim 1, characterized in that, The solvent for the alkaline zinc-based flow battery electrolyte is water.

6. A method for preparing an alkaline zinc-based flow battery electrolyte based on a zinc anode interface control strategy as described in any one of claims 1-5, characterized in that, Includes the following steps: The zinc active material, additives, and supporting electrolyte are added to a solvent and mixed evenly to obtain the alkaline zinc-based flow battery electrolyte.

7. The application of an alkaline zinc-based flow battery electrolyte based on a zinc anode interface regulation strategy as described in any one of claims 1-5 in the anode electrolyte of an alkaline zinc-based flow battery.

8. The application according to claim 7, characterized in that, The alkaline zinc-based flow battery includes one of the following: zinc-iron battery, zinc-iodine battery, zinc-sulfur battery, zinc-bromine battery, zinc-manganese battery, zinc-nickel battery, and zinc-air battery.

9. An alkaline zinc-based flow battery, comprising a positive electrode, a negative electrode, a positive electrolyte, a negative electrolyte, and a battery separator, characterized in that, The negative electrode electrolyte is the alkaline zinc-based flow battery electrolyte according to any one of claims 1-5.

10. An alkaline zinc-based flow battery according to claim 9, characterized in that, The battery separator includes one or more of the following: perfluorosulfonic acid proton exchange membrane, sulfonated polyether ether ketone membrane, and polybenzimidazole membrane.

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