Additive-containing salt-cavern electrolyte and aqueous organic flow battery

Abstract

The invention discloses an additive-containing salt-cavern electrolyte and an aqueous organic flow battery, and belongs to the technical field of flow batteries. The barium salt, the calcium salt and the magnesium salt are introduced into the electrolyte to form precipitation substances and part of acidic substances as functional additives, so that the interference of carbonate ions is effectively eliminated, the reversible stability of organic electrolyte molecules is remarkably improved, and the cycle life of the battery is prolonged. Meanwhile, the additive can form a stable hydrated ion structure with free water, the amount of free water is reduced, hydrogen bond fracture energy is improved, and side reactions such as hydrogen evolution are remarkably inhibited. In addition, the additive inhibits aggregation and degradation behaviors of electrolyte molecules by constructing an ion barrier effect, and improves system stability and energy efficiency. The salt-cavern electrolyte containing the additive provides a new solution and a technical path for large-scale energy storage application of an aqueous organic flow battery in a salt-cavern environment.

Description

Technical Field

[0001] The present invention belongs to the technical field of aqueous organic liquid flow batteries, and in particular relates to a salt cavern electrolyte containing an additive and an aqueous organic liquid flow battery. Background Art

[0002] With the rapid development of renewable energy sources such as solar and wind power, efficient energy storage technologies are urgently needed to balance electricity supply and demand. Aqueous flow batteries have become a research hotspot for large-scale energy storage due to their good scalability, intrinsic safety, and long service life. Traditional flow batteries usually consist of two tanks storing liquid electrolytes and an electrochemical reaction unit. They rely on the flow of electrolytes between electrodes to carry out electrochemical reactions to store and release energy. They have advantages such as fast charging and discharging and modular deployment. However, existing aqueous flow batteries still have problems such as low energy density, limited conversion efficiency, and insufficient operating current density. Especially in large-scale energy storage scenarios, traditional flow batteries require large ground storage tanks, which occupy a large area (for example, a 200MW / 800MWh energy storage power station can occupy up to 50,000 square meters) and have high construction costs, which restrict the further expansion of system capacity and commercialization.

[0003] To this end, salt cavern flow batteries have emerged. This technology, which relies on natural underground salt caverns to store large volumes of electrolyte, not only significantly increases system installed capacity, reduces unit energy footprint and infrastructure costs, but also demonstrates promising commercial application potential. However, direct application of salt cavern solutions still faces challenges. Natural salt cavern solutions contain a complex array of ions. Hydroxides generated by the hydrolysis of carbonate ions can increase the solution's pH, in turn inducing side reactions such as electrolyte decomposition. This affects the stability of the active material and the battery's cycling performance, hindering the practical application of salt cavern flow batteries. Summary of the Invention

[0004] The present invention aims to overcome the shortcomings of the above-mentioned prior art and provide a salt cavern electrolyte and an aqueous organic liquid flow battery containing an additive, so as to solve the problem in the prior art that when the salt cavern solution is directly used as the electrolyte of the aqueous liquid flow battery, the presence of some negative ions leads to poor battery cycle stability.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A salt cavern electrolyte containing an additive, wherein the salt cavern electrolyte is used as a positive electrode electrolyte or a negative electrode electrolyte, or as both a positive electrode electrolyte and a negative electrode electrolyte;

[0007] The salt cave electrolyte includes a salt cave solution, organic redox active molecules and additives;

[0008] The additive is one or more of calcium chloride or its hydrate, barium chloride or its hydrate, magnesium chloride or its hydrate, and hydrochloric acid.

[0009] A further improvement of the present invention is:

[0010] Preferably, the concentration of the additive in the electrolyte is 0.001 mol / L to 2.0 mol / L.

[0011] Preferably, the concentration of the additive in the electrolyte is 0.03 mol / L to 1.0 mol / L.

[0012] Preferably, the concentration of the organic redox active molecules is 0.05 mol / L to 3.0 mol / L.

[0013] Preferably, the organic redox active molecule in the positive electrode electrolyte is any one of a cyclic nitroxide free radical derivative, a benzoquinone derivative and an iron-based complex derivative.

[0014] Preferably, the organic redox active molecule in the negative electrode electrolyte is any one of a viologen derivative, an imide derivative, an oxazine derivative and an anthraquinone derivative.

[0015] An aqueous organic liquid flow battery comprises a positive electrode electrolyte and a negative electrode electrolyte, wherein the positive electrode electrolyte or the negative electrode electrolyte adopts the above-mentioned salt cave electrolyte.

[0016] Preferably, the organic redox active molecule in the negative electrode electrolyte is 1,1-dimethyl-4,4'-bipyridinium dichloride, the organic redox active molecule in the positive electrode electrolyte is trimethylammonium-2,2,6,6-tetramethylpiperidinium-1-oxyl free radical chloride, and the additive of the positive electrode electrolyte is calcium chloride or its hydrate.

[0017] Preferably, the concentration of the 1,1-dimethyl-4,4'-bipyridinium dichloride in the negative electrode electrolyte is 0.05 mol / L, and calcium chloride or its hydrate is also added to the negative electrode electrolyte.

[0018] Preferably, the concentration of trimethylammonium-2,2,6,6-tetramethylpiperidin-1-oxyl radical chloride in the positive electrode electrolyte is 0.05 mol / L, and calcium chloride or its hydrate is also added to the positive electrode electrolyte.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention discloses a salt cave electrolyte containing additives, wherein the salt cave electrolyte contains barium salts, calcium salts, magnesium salts and some acidic substances to eliminate the effects of carbonate ions. On the one hand, the additives can eliminate carbonate ions, greatly improve the reversible stability of electrolyte molecules, and extend the life of the flow battery, providing a new design idea and solution for high-performance salt cave aqueous organic flow batteries. On the other hand, the additives form hydrated ions with free water in the solution, reducing the amount of free water, increasing the difficulty of hydrogen bond breaking, effectively reducing the occurrence of side reactions such as hydrogen evolution, and forming ion barriers to inhibit the aggregation of electrolyte molecules. In addition, compared with the chemical modification method, the additive strategy has the advantages of being simple and easy to operate, suitable for the mass preparation of high-performance electrolytes, and providing a new idea for the practical application of flow battery performance; this method effectively maintains the redox reversible stability of organic redox active molecules, extends the life of salt cave aqueous organic flow batteries, and provides a new approach and idea for realizing large-scale energy storage of salt cave aqueous organic flow batteries.

[0021] Specifically, the present invention combines metal cations (such as calcium, barium, and magnesium) with carbonate ions to form corresponding carbonate precipitates. Acids react with carbonate ions, typically producing carbon dioxide to remove the carbonate ions. Furthermore, the principles used in the present invention to remove carbonate ions are also applicable to other side effect ions, which can be removed by converting the side effect ions into gaseous or precipitated forms. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The changes in discharge capacity, coulombic efficiency, and energy efficiency during cycling for the trimethylammonium-2,2,6,6-tetramethylpiperidin-1-oxyl free radical chloride cathode electrolyte containing 0.03 mol / L sodium carbonate additive in Comparative Example 1 of the present invention (the supporting electrolyte was a 1 mol / L NaCl solution).

[0023] Figure 2 This is the change in battery discharge capacity, coulombic efficiency, and energy efficiency during the cycle of the trimethylammonium-2,2,6,6-tetramethylpiperidin-1-oxyl free radical chloride positive electrode electrolyte in Comparative Example 2 of the present invention, which does not contain ionic additives (the supporting electrolyte is a salt cave solution).

[0024] Figure 3 The changes in discharge capacity, coulombic efficiency, and energy efficiency during cycling of the trimethylammonium-2,2,6,6-tetramethylpiperidin-1-oxyl free radical chloride cathode electrolyte containing 0.03 mol / L sodium carbonate and 0.03 mol / L calcium chloride additives in Example 1 of the present invention (the supporting electrolyte was a 1 mol / L NaCl solution).

[0025] Figure 4This is the change in battery discharge capacity, coulombic efficiency, and energy efficiency during the cycle of the trimethylammonium-2,2,6,6-tetramethylpiperidin-1-oxyl free radical chloride positive electrolyte containing 0.25 mol / L calcium chloride additive in Example 2 of the present invention (the supporting electrolyte is a salt cave solution).

[0026] Figure 5 This is the change in battery discharge capacity during the cycle of the 2,6-dihydroxyanthraquinone positive electrode electrolyte containing 0.25 mol / L calcium chloride additive in Example 3 of the present invention (the supporting electrolyte is a salt cave solution).

[0027] Figure 6 This is the change in battery discharge capacity during the cycle of the ferrocenylmethyl quaternary ammonium salt positive electrode electrolyte containing 0.25 mol / L calcium chloride additive in Example 4 of the present invention (the supporting electrolyte is a salt cave solution).

[0028] Figure 7 This is the change in battery discharge capacity during the cycling process of the naphthalene diimide negative electrode electrolyte containing 0.25 mol / L calcium chloride additive in Example 5 of the present invention (the supporting electrolyte is a salt cave solution). DETAILED DESCRIPTION

[0029] The present invention is described in further detail below with reference to the accompanying drawings:

[0030] To facilitate understanding of the features and effects of the present invention by those skilled in the art, the following provides a general description and definition of the terms and expressions used in the specification and claims. Unless otherwise indicated, all technical and scientific terms used herein have the ordinary meanings as understood by those skilled in the art regarding the present invention. In the event of conflict, the definitions in this specification shall prevail.

[0031] In this document, unless otherwise specified, “include,” “including,” “contains,” “has” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0032] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0033] The following examples were prepared using conventional instruments and equipment in the art. Experimental methods in the following examples, where specific conditions are not specified, were generally performed under conventional conditions or according to the conditions recommended by the manufacturer. The various raw materials used in the following examples, unless otherwise specified, were conventional commercially available products, with specifications conventional in the art. In the present specification and the following examples, unless otherwise specified, "%" indicates percentage by weight, "part" indicates parts by weight, and "ratio" indicates weight ratio.

[0034] As the background technology raises the question, a large amount of mineral salts, such as sodium chloride, potassium chloride, sodium carbonate, sodium sulfate, etc., are dissolved in the salt cave solution, and most of them are saturated solutions. In particular, there are a large number of carbonate ions. Carbonate ions are easily hydrolyzed to produce hydroxide ions. Hydroxyl ions will react with active molecules, resulting in the destruction of the structure of organic redox active molecules, which significantly reduces the stability of the battery. Carbonate ions will also bring about water decomposition side reactions, causing the battery energy efficiency and coulombic efficiency to continue to decrease, resulting in reduced reversible stability of electrolyte molecules and shortened life of the flow battery.

[0035] The invention discloses an additive-containing salt cavern aqueous organic liquid flow battery electrolyte, which can be used as a positive electrode electrolyte or a negative electrode electrolyte.

[0036] The electrolyte comprises a salt cave solution, organic redox active molecules and additives; the additives are one or more of calcium chloride or its hydrate, barium chloride or its hydrate, magnesium chloride or its hydrate, and hydrochloric acid.

[0037] On this basis, according to the solubility product of each precipitate and the solubility of the gas, the more preferred additive is calcium chloride, which can better combine with carbonate ions.

[0038] The additive can be added to the positive electrode electrolyte alone or to the negative electrode electrolyte alone or to the positive and negative electrode electrolytes at the same time to form an aqueous organic liquid flow battery.

[0039] In some embodiments of the present invention, the concentration of the organic redox active molecules in the electrolyte is 0.05 mol / L to 3.0 mol / L. Within this concentration range, the organic redox active molecules can repeatedly undergo redox reactions and transfer electrons during battery operation.

[0040] In some embodiments of the present invention, the concentration of the additive in the electrolyte is 0.005 mol / L to 2.0 mol / L; within this range, the additive can fully react with carbonate ions to avoid the influence of carbonate ions on redox molecules.

[0041] As a preferred solution, the concentration of the additive in the electrolyte is 0.03 mol / L to 1.0 mol / L, which can fully react with carbonate ions and form hydrated ions with free water to reduce the amount of free water.

[0042] In some embodiments of the present invention, the redox active substance in the positive electrolyte is any one of cyclic nitroxide free radical derivatives, benzoquinones and their derivatives, and iron-based complex derivatives.

[0043] In some embodiments of the present invention, the redox active substance in the negative electrode electrolyte is any one of a viologen derivative, an imide derivative, an oxazine derivative, and an anthraquinone derivative.

[0044] The specific structural formulas of the above substances are shown in Table 1 below.

[0045] Table 1 Organic redox active substances

[0046]

[0047] Among them, R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 、R 11 、R 12 Each of the following independently represents one of the following: alkyl, hydrogen, halogen, methyl fluoride, difluoromethyl, trifluoromethyl, haloalkyl, aralkyl, alkoxy, cycloalkyl, heterocyclic, hydroxy, nitro, amino, cyano, ester, ether chain, alkenyl chain, amide, quaternary ammonium salt cation, quaternary phosphate cation, imidazolium cation, phosphate anion, sulfonate anion, carboxylate anion, etc.

[0048] Based on the above substances, preferably, the structural formulas of the viologen derivatives, imide derivatives, quinone derivatives, cyclic nitroxide free radical derivatives, and iron-based complex derivatives used in the embodiments of the present invention are shown in Table 2 below.

[0049] Table 2 Some redox active substances

[0050]

[0051] In a specific embodiment of the present invention, the concentration of 1,1-dimethyl-4,4'-bipyridinium dichloride in the negative electrode electrolyte is 0.05 mol / L.

[0052] In a specific embodiment of the present invention, the concentration of naphthalene diimide in the negative electrode electrolyte is 0.1 mol / L.

[0053] In a specific embodiment of the present invention, the concentration of 2,6-dihydroxyanthraquinone in the positive electrode electrolyte is 0.1 mol / L.

[0054] In a specific embodiment of the present invention, the concentration of trimethylammonium-2,2,6,6-tetramethylpiperidin-1-oxyl radical chloride in the positive electrode electrolyte is 0.05 mol / L.

[0055] In a specific embodiment of the present invention, the concentration of 2,2,6,6-tetramethylpiperidinyloxy-4-potassium sulfate in the positive electrode electrolyte is 0.1 mol / L.

[0056] In a specific embodiment of the present invention, the concentration of ferrocenylmethyl quaternary ammonium salt in the positive electrode electrolyte is 0.1 mol / L.

[0057] In a specific embodiment of the present invention, the concentration of the supporting electrolyte (sodium chloride) in the negative electrode electrolyte and the positive electrode electrolyte is 1.0 mol / L.

[0058] The following is further explained with reference to specific comparative examples and embodiments.

[0059] Comparative Example 1

[0060] Flow battery experiments were conducted using an aqueous solution containing 0.05 mol / L trimethylammonium-2,2,6,6-tetramethylpiperidin-1-oxyl chloride (an organic redox-active molecule) and 1 mol / L NaCl as the positive electrolyte, and an aqueous solution containing 0.05 mol / L 1,1-dimethyl-4,4'-bipyridinium dichloride (an organic redox-active molecule) and 1 mol / L NaCl as the negative electrolyte. The volume of the negative electrolyte was 1.5 times that of the positive electrolyte. The experiments were conducted under nitrogen protection, using carbon felt electrodes, and at an electrolyte flow rate of 60 mL / min. Sodium carbonate was added to the positive electrolyte to maintain a concentration of 0.03 mol / L. Charge and discharge experiments were conducted in a constant current constant voltage charge-constant current constant voltage discharge mode. Figure 1 The figure below shows the discharge capacity retention of batteries containing sodium carbonate as an additive. As can be seen from the figure, the capacity retention of batteries containing sodium carbonate as an additive is significantly reduced. Furthermore, the average energy efficiency and coulombic efficiency of batteries containing sodium carbonate as an additive are also extremely unstable.

[0061] Comparative Example 2

[0062] A flow battery experiment was conducted using 0.05 mol / L trimethylammonium-2,2,6,6-tetramethylpiperidin-1-oxyl chloride, a redox-active organic molecule, as the positive electrode active material, 0.05 mol / L 1,1-dimethyl-4,4'-bipyridinium dichloride as the negative electrode active material, and a salt cavern solution as the supporting electrolyte. The volume of the negative electrode electrolyte was maintained at 1.5 times that of the positive electrode. The electrolyte was protected by nitrogen, carbon felt electrodes were used, and the electrolyte flow rate was 60 mL / min. Charge and discharge experiments were conducted in a constant current constant voltage charge-constant current constant voltage discharge mode. Figure 2 The figure below shows the discharge capacity retention of a battery without any additives. As can be seen from the figure, the battery capacity retention rate has dropped significantly. Furthermore, the battery's average energy efficiency and coulombic efficiency are also extremely unstable.

[0063] Example 1

[0064] A flow battery experiment was conducted using an aqueous solution containing 0.05 mol / L trimethylammonium-2,2,6,6-tetramethylpiperidin-1-oxyl radical chloride, an organic redox active molecule, and 1 mol / L NaCl as a supporting electrolyte, as the positive electrode electrolyte. The aqueous solution containing 0.05 mol / L 1,1-dimethyl-4,4'-bipyridinium dichloride, an organic redox active molecule, and 1 mol / L NaCl as a supporting electrolyte, keeping the volume of the negative electrode electrolyte 1.5 times that of the positive electrode. During the experiment, the electrolyte was protected by nitrogen, a carbon felt electrode was used, and the flow rate of the electrolyte was 60 mL / min. The charge and discharge experiments were carried out in a constant current constant voltage charge-constant current constant voltage discharge mode. 0.03 mol / L sodium carbonate and 0.03 mol / L calcium chloride were added to the positive electrode electrolyte in the battery, and they were all converted into calcium carbonate precipitates. The solution did not contain any carbonate ions. Figure 3 This is a graph showing the discharge capacity retention rate of the battery after carbonate ions are precipitated.

[0065] Comparative Example 1 Figure 1 and Example 1 Figure 3 It can be found that the capacity retention rate of the battery without carbonate ions is significantly improved, and the average energy efficiency and coulombic efficiency of the battery are also maintained at a high level. Therefore, it can be seen that the presence of carbonate ions reduces the reversible stability of the redox electrolyte and affects the battery life.

[0066] Example 2

[0067] A flow battery experiment was conducted using 0.05 mol / L trimethylammonium-2,2,6,6-tetramethylpiperidin-1-oxyl chloride, a redox-active organic molecule, as the positive electrode active material, 0.05 mol / L 1,1-dimethyl-4,4'-bipyridinium dichloride as the negative electrode active material, and a salt cavern solution as the supporting electrolyte. The volume of the negative electrode electrolyte was maintained at 1.5 times that of the positive electrode. The electrolyte was protected by nitrogen, carbon felt electrodes were used, and the electrolyte flow rate was 60 mL / min. Calcium chloride was added to the positive electrode electrolyte to maintain a concentration of 0.25 mol / L. Charge and discharge experiments were conducted in a constant current constant voltage charge-constant current constant voltage discharge mode. Figure 4 This is a graph showing the discharge capacity retention rate of batteries containing calcium chloride additives.

[0068] Combined with Comparative Example 2 Figure 2 and this embodiment Figure 4 The comparison shows that under the same salt cavern solution conditions, the battery capacity retention rate of the battery containing calcium chloride additive is significantly improved. In addition, the average energy efficiency and coulombic efficiency of the battery containing calcium chloride additive are also maintained at a high level.

[0069] Example 3

[0070] A flow battery experiment was conducted using 0.1 mol / L 2,2,6,6-tetramethylpiperidinyloxy-4-potassium sulfate as the positive electrode active material, 0.1 mol / L 2,6-dihydroxyanthraquinone as the negative electrode active material, and a salt cave solution as the supporting electrolyte. The volume of the negative electrode electrolyte was kept 1.5 times that of the positive electrode. During the experiment, the electrolyte was protected by nitrogen, a carbon felt electrode was used, and the flow rate of the electrolyte was 60 mL / min. Calcium chloride was added to the positive electrode electrolyte in the battery to ensure that its concentration was 0.25 mol / L, and the charge and discharge experiments were carried out in a constant current constant voltage charge-constant current constant voltage discharge mode. Figure 5 This is a graph of the discharge capacity retention rate of the battery containing calcium chloride additive. It can be seen from the graph that the discharge capacity of the battery containing calcium chloride additive decreases slowly, which inhibits capacity attenuation to a certain extent.

[0071] Example 4

[0072] A flow battery experiment was conducted using 0.1 mol / L ferrocenylmethyl quaternary ammonium salt containing the organic redox-active molecule as the positive electrode active material, 0.1 mol / L 1,1-dimethyl-4,4'-bipyridinium dichloride as the negative electrode active material, and a salt cavern solution as the supporting electrolyte. The volume of the negative electrode electrolyte was maintained at 1.5 times that of the positive electrode. The electrolyte was protected by nitrogen, carbon felt electrodes were used, and the electrolyte flow rate was 60 mL / min. Calcium chloride was added to the positive and negative electrolytes to maintain a concentration of 0.25 mol / L. Charge and discharge experiments were conducted in a constant current constant voltage charge-constant current constant voltage discharge mode. Figure 6 This is a graph of the discharge capacity retention rate of a battery containing calcium chloride additive. It can be seen from the graph that when calcium chloride is added to the positive electrode electrolyte, the discharge capacity of the battery fluctuates with the increase in the number of cycles, but basically remains stable.

[0073] Example 5

[0074] A flow battery experiment was conducted using 0.1 mol / L trimethylammonium-2,2,6,6-tetramethylpiperidin-1-oxyl chloride, a redox-active organic molecule, as the positive electrode active material, 0.1 mol / L naphthalene diimide as the negative electrode active material, and a salt cavern solution as the supporting electrolyte. The volume of the negative electrode electrolyte was maintained at 1.5 times that of the positive electrode. The electrolyte was protected by nitrogen, carbon felt electrodes were used, and the electrolyte flow rate was 60 mL / min. Calcium chloride was added to both the positive and negative electrolytes to maintain a concentration of 0.25 mol / L. Charge and discharge experiments were conducted in a constant current constant voltage charge-constant current constant voltage discharge mode. Figure 7 3 is a graph showing the discharge capacity retention rate of a battery containing a calcium chloride additive. As can be seen from the graph, in this embodiment, as the number of cycles increases, the discharge capacity of the battery remains stable.

[0075] Example 6

[0076] The battery uses 0.1 mol / L 2,2,6,6-tetramethylpiperidinyloxy-4-potassium sulfate (a redox-active organic molecule) as the positive active material, 0.1 mol / L 1,6-dihydroxyphenazine as the negative active material, and a salt cave solution as the supporting electrolyte. The volume of the negative electrolyte is maintained at 1.5 times that of the positive. Calcium chloride is added to both the positive and negative electrolytes to maintain a concentration of 0.005 mol / L.

[0077] Example 7

[0078] 2.0 mol / L trimethylammonium-2,2,6,6-tetramethylpiperidin-1-oxyl radical chloride containing an organic redox active molecule is used as the positive electrode active material, 2.0 mol / L 1,1-dimethyl-4,4'-bipyridinium dichloride is used as the negative electrode active material, and salt cave solution is used as the supporting electrolyte. The volume of the negative electrode electrolyte is kept 1.5 times that of the positive electrode. Barium chloride is added to both the positive and negative electrode electrolytes in the battery to ensure that their concentration is 0.01 mol / L.

[0079] Example 8

[0080] 1.5 mol / L trimethylammonium-2,2,6,6-tetramethylpiperidin-1-oxyl radical chloride containing an organic redox active molecule is used as the positive electrode active material, 1.5 mol / L 1,1-dimethyl-4,4'-bipyridinium dichloride is used as the negative electrode active material, and salt cave solution is used as the supporting electrolyte. The volume of the negative electrode electrolyte is maintained at 1.5 times that of the positive electrode. Magnesium chloride is added to both the positive and negative electrode electrolytes in the battery to ensure that their concentration is 0.03 mol / L.

[0081] Example 9

[0082] 0.1 mol / L trimethylammonium-2,2,6,6-tetramethylpiperidin-1-oxyl radical chloride containing an organic redox active molecule is used as the positive electrode active material, 0.1 mol / L 1,1-dimethyl-4,4'-bipyridinium dichloride is used as the negative electrode active material, and a salt cave solution is used as the supporting electrolyte. The volume of the negative electrode electrolyte is maintained at 1.5 times that of the positive electrode. Hydrochloric acid is added to both the positive and negative electrode electrolytes in the battery to ensure that their concentrations are 1.0 mol / L.

[0083] Example 10

[0084] 3.0 mol / L trimethylammonium-2,2,6,6-tetramethylpiperidin-1-oxyl radical chloride containing an organic redox active molecule is used as the positive electrode active material, 3.0 mol / L 1,1-dimethyl-4,4'-bipyridinium dichloride is used as the negative electrode active material, and a salt cave solution is used as the supporting electrolyte. The volume of the negative electrode electrolyte is maintained at 1.5 times that of the positive electrode. Calcium chloride is added to both the positive and negative electrode electrolytes in the battery to ensure that their concentrations are 2.0 mol / L.

[0085] Example 11

[0086] 0.05 mol / L trimethylammonium-2,2,6,6-tetramethylpiperidin-1-oxyl radical chloride containing an organic redox active molecule is used as the positive electrode active material, 0.05 mol / L 1,1-dimethyl-4,4'-bipyridinium dichloride is used as the negative electrode active material, and salt cave solution is used as the supporting electrolyte. The volume of the negative electrode electrolyte is kept 1.5 times that of the positive electrode. Calcium chloride is added to both the positive and negative electrode electrolytes in the battery to ensure that their concentration is 0.1 mol / L.

[0087] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. Salt cave electrolyte containing additives, characterized in that: The salt cave electrolyte is used as the positive electrode electrolyte or the negative electrode electrolyte, or as both the positive electrode electrolyte and the negative electrode electrolyte; The salt cave electrolyte includes a salt cave solution, organic redox active molecules and additives; The additive is one or more of calcium chloride or its hydrate, barium chloride or its hydrate, magnesium chloride or its hydrate, and hydrochloric acid.

2. The salt cave electrolyte containing additives according to claim 1, characterized in that: The concentration of the additive in the electrolyte is 0.005 mol / L to 2.0 mol / L.

3. The salt cave electrolyte containing additives according to claim 1, characterized in that: The concentration of the additive in the electrolyte is 0.03 mol / L to 1.0 mol / L.

4. The salt cave electrolyte containing additives according to claim 1, characterized in that The concentration of the organic redox active molecules is 0.05 mol / L to 3.0 mol / L.

5. The salt cave electrolyte containing additives according to claim 1, characterized in that: The organic redox active molecule in the positive electrode electrolyte is any one of a cyclic nitroxide free radical derivative, a benzoquinone derivative and an iron-based complex derivative.

6. The salt cave electrolyte containing additives according to claim 1, characterized in that: The organic redox active molecule in the negative electrode electrolyte is any one of a viologen derivative, an imide derivative, an oxazine derivative and an anthraquinone derivative.

7. An aqueous organic liquid flow battery, characterized in that: The invention comprises a positive electrode electrolyte and a negative electrode electrolyte, wherein the positive electrode electrolyte or the negative electrode electrolyte adopts the salt cave electrolyte according to claim 1.

8. The aqueous organic liquid flow battery according to claim 7, characterized in that The organic redox active molecule in the negative electrode electrolyte is 1,1-dimethyl-4,4'-bipyridinium dichloride, the organic redox active molecule in the positive electrode electrolyte is trimethylammonium-2,2,6,6-tetramethylpiperidinium-1-oxyl free radical chloride, and the additive of the positive electrode electrolyte is calcium chloride or its hydrate.

9. The aqueous organic liquid flow battery according to claim 8, characterized in that The concentration of the 1,1-dimethyl-4,4'-bipyridinium salt dichloride in the negative electrode electrolyte is 0.05 mol / L, and calcium chloride or its hydrate is added to the negative electrode electrolyte.

10. The aqueous organic liquid flow battery according to claim 8, characterized in that The concentration of the trimethylammonium-2,2,6,6-tetramethylpiperidin-1-oxyl free radical chloride in the positive electrode electrolyte is 0.05 mol / L, and calcium chloride or its hydrate is added to the positive electrode electrolyte.

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