Hexaazaphthalene-based multi-electron aqueous flow battery energy storage material

Abstract

The invention provides an energy storage material based on a hexaaza-naphthalene multi-electron aqueous flow battery, and particularly provides a hexaaza-naphthalene multi-electron compound which can be used as the energy storage material of the aqueous flow battery. The preparation method of the compound is simple, and the prepared battery energy storage material has relatively good cycling stability and energy efficiency and is suitable for being used as an energy storage material of an aqueous flow battery.

Description

Technical Field

[0001] The present invention provides a multi-electron aqueous organic liquid flow battery energy storage material based on a hexaazanaphthalene mother core structure, and specifically relates to several water-soluble organic active materials based on a hexaazanaphthalene mother core, and their applications in liquid flow batteries. Background Art

[0002] In order to achieve "carbon peak" and "carbon neutrality", it is urgent to develop new energy and realize energy transformation to reduce the consumption of fossil energy. However, due to the intermittent and volatile nature of wind speed, wind direction, day and night, cloudy and sunny weather, in order to ensure the safe, stable and reliable power supply of the power grid, it is necessary to develop efficient, sustainable and low-cost energy conversion and storage technologies. Electrochemical storage is the most effective method of energy storage and conversion.

[0003] Aqueous organic flow batteries mainly rely on the redox reaction of energy storage active substances to achieve energy storage and release. Due to the characteristics of energy and power being independent of each other, high safety, and adjustable energy storage scale, they have great application prospects in the field of large-scale energy storage. However, there is a solubility limit of active substances in water, which restricts the energy density of aqueous flow batteries. The industrial development of aqueous flow batteries is limited by key issues such as low energy density and high cost. Therefore, the development of highly water-soluble, multi-electron transfer organic energy storage molecules can greatly improve the capacity density and energy density of batteries.

[0004] The parent nucleus of hexaazanaphthalene and its derivatives has three nitrogen aromatic rings, which can realize the transfer of six electrons during the redox process. This patent is based on the design of the hexaazanaphthalene parent nucleus and develops a series of highly water-soluble and electrochemically stable energy storage active materials. The synthesis route is simple and efficient, and it is easy to expand mass production. Hexaazanaphthalene active materials exhibit a high redox potential in aqueous batteries. Its redox potential can adapt to the working conditions of aqueous liquid flow batteries. It maintains a stable electron transfer ability during the charging and discharging process, and can realize the transfer process of up to six electrons, which is beneficial to improve the energy density. When used in aqueous liquid flow batteries, it usually exhibits high cycle stability and can maintain a low capacity decay rate over multiple charge and discharge cycles. In aqueous liquid flow batteries, its application can not only improve the overall performance of the battery, but also reduce costs and extend service life, providing a feasible solution for the development of green and efficient energy storage systems.

[0005] In summary, there is an urgent need in the art for a hexaazine-based multi-electron aqueous liquid flow battery energy storage material. Summary of the invention

[0006] The purpose of the present invention is to provide a multi-electron aqueous liquid flow battery energy storage material based on hexaazine.

[0007] The first aspect of the present invention provides a compound shown in the following formula:

[0008]

[0009] Wherein, Y and Z are each independently selected from the following group: N, CH;

[0010] m is selected from the group consisting of 0, 1, 2 or 3;

[0011] R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 Each is independently selected from the following group: H, halogen, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C2-C10 alkenyl, cycloalkyl, heterocycloalkyl, substituted or unsubstituted C6-C10 aryl, hydroxyl, thiol, amine, carboxyl, phosphate, sulfonic acid, or the following water-soluble groups:

[0012] Where n is 1, 2, 3, 4, 5, 6, 7, 8; and R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 At least one of them is the water-soluble group; preferably at least three of them are the water-soluble groups;

[0013] A is O, S or a chemical bond; R 0 Selected from the following group: -COOX, -SO 3 X, -PO 3 X, -NH 2 ·HQ, -NHCH 3 ·HQ, -N(CH 3 ) 2 ·HQ, -N + (CH 3 ) 3 M - ; wherein X is selected from the following group: H + NH4 + , Li + 、Na + , K + Mg 2+ 、Al 3+ , Ca 2+ ;M - Select from the following group: F - , Cl - Br - ,I - OH - ,OAc - ,OTf - ,OTs - 、SO 4 2- 、SO 3 2- ,PO 4 3- , HPO 4 2- , H 2 PO 4 - 、NO 2 - 、NO 3 - , CO 3 2- , HCO 3 - , ClO 4 - , ClO 3 - , ClO 2 - , ClO - , CN - etc.; Q is selected from the following group: Cl - , SO 4 2- , Y is selected from the group consisting of O, NH, NMe, CH 2 ;

[0014] R p , R q Each is independently selected from the following group: H, substituted or unsubstituted C1-C10 alkyl, cycloalkyl, heterocycloalkyl, or substituted or unsubstituted C6-C10 aryl;

[0015] The substitution refers to that one or more hydrogen atoms on the group are replaced by a substituent selected from the following group: halogen, C1-C6 alkyl, C6-C10 aryl, hydroxyl, thiol group, amine group, carboxyl group, phosphate group, sulfonic acid group.

[0016] In another preferred embodiment, the compound is selected from the following group: wherein Y and Z are each independently N.

[0017] In another preferred embodiment, the R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 Each is independently selected from the following group: H, halogen, substituted or unsubstituted C1-C10 alkyl, cycloalkyl, heterocycloalkyl, hydroxyl, thiol, amine, carboxyl, phosphoric acid, sulfonic acid, or the following water-soluble groups:

[0018] Wherein, n is 1, 2, 3, 4, 5, 6, 7, 8;

[0019] A is O, S or a chemical bond; R 0 Selected from the following group: -COOX, -SO 3 X, -PO 3 X, -NH 2 ·HQ, -NHCH 3 ·HQ, -N(CH 3 ) 2 ·HQ, -N + (CH 3 ) 3 M - ; wherein X is selected from the following group: H + NH 4 + , Li + 、Na + , K + Mg 2+ 、Al 3+ , Ca 2+ ;M - Select from the following group: F - , Cl - Br - ,I - OH - ,OAc - ,OTf - ,OTs - 、SO 4 2- 、SO 3 2- ,PO 4 3- , HPO4 2- , H 2 PO 4 - 、NO 2 - 、NO 3 - , CO 3 2- , HCO 3 - , ClO 4 - , ClO 3 - , ClO 2 - , ClO - , CN - etc.; Q is selected from the following group: Cl - , SO 4 2- , Y is selected from the group consisting of O, NH, NMe, CH 2 ;

[0020] R p , R q Each is independently selected from the following group: H, substituted or unsubstituted C1-C10 alkyl, cycloalkyl, heterocycloalkyl, or substituted or unsubstituted C6-C10 aryl;

[0021] The substitution refers to that one or more hydrogen atoms on the group are replaced by a substituent selected from the following group: halogen, C1-C6 alkyl, C6-C10 aryl, hydroxyl, thiol group, amine group, carboxyl group, phosphate group, sulfonic acid group.

[0022] In another preferred embodiment, the R 1 , R 4 , R 5 , R 8 , R 9 , R 12 Each independently is H; R 2 , R 3 , R 6 , R 7 , R 10 and R 11 Each independently selected from the following group: substituted or unsubstituted C1-C10 alkyl, hydroxyl, thiol, amine, carboxyl, phosphoric acid, sulfonic acid, or the following water-soluble groups Wherein, n is 1, 2, 3, 4, 5, 6, 7, 8;

[0023] A is O, S or a chemical bond; R 0 Selected from the following group: -COOX, -SO 3X, -PO 3 X, -NH 2 ·HQ, -NHCH 3 ·HQ, -N(CH 3 ) 2 ·HQ, -N + (CH 3 ) 3 M - ; wherein X is selected from the following group: H + NH 4 + , Li + 、Na + , K + Mg 2+ 、Al 3+ , Ca 2+ ;M - Select from the following group: F - , Cl - Br - ,I - OH - ,OAc - ,OTf - ,OTs - 、SO 4 2- 、SO 3 2- ,PO 4 3- , HPO 4 2- , H 2 PO 4 - 、NO 2 - 、NO 3 - , CO 3 2- , HCO 3 - , ClO 4 - , ClO 3 - , ClO 2 - , ClO - , CN - ; Q is selected from the following group: Cl - , SO 4 2- ; Y is selected from the group consisting of O, NH, NMe, CH 2 .

[0024] In another preferred embodiment, the compound has a structure shown in the following formula:

[0025]

[0026] In another preferred embodiment, the compound is selected from the following group:

[0027]

[0028] In another preferred embodiment, the method comprises the steps of:

[0029]

[0030] In the presence of a condensing agent, (Ia-1) and (Ia-2) are reacted to obtain a compound of formula (Ia); wherein R 1 , R 4 , R 5 , R 8 , R 9 , R 12 Each is independently H; preferably, the reaction is carried out in an ethanol solution; more preferably, the condensation agent is acetic acid.

[0031] The second aspect of the present invention provides a liquid flow battery energy storage material, wherein the liquid flow battery energy storage material is prepared using the compound described in the first aspect of the present invention as an active ingredient.

[0032] The third aspect of the present invention provides a liquid flow battery, wherein the liquid flow battery comprises the compound as described in the first aspect of the present invention as an energy storage material.

[0033] In another preferred embodiment, in the liquid flow battery, the compound described in the present invention is used as the negative electrode or positive electrode solution.

[0034] It should be understood that within the scope of the present invention, the above-mentioned technical features of the present invention and the technical features specifically described below (such as embodiments) can be combined with each other to form a new or preferred technical solution. Due to space limitations, they will not be described one by one here. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is the cyclic voltammogram of compound 1 in 1M KOH solution;

[0036] Figure 2 is the cyclic voltammogram of compound 2 in 1M KOH solution;

[0037] Figure 3 is the cyclic voltammogram of compound 3 in 1M KOH solution;

[0038] Figure 4 is the cyclic voltammogram of compound 4 in 1M KCl solution;

[0039] Figure 5 is the cyclic voltammogram of compound 5 in 1M KOH solution;

[0040] Figure 6 and 7 The charge-discharge cycle test results of 0.1M compound 1 in 1M KOH solution;

[0041] Figure 8 and 9 The charge-discharge cycle test results of high concentration (0.4M) compound 1 in 1M KOH solution;

[0042] Fig.10 This is the single crystal structure diagram of compound C;

[0043] Fig.11 and 12 The charge-discharge cycle test results of 0.1M compound 5 in 1M KOH solution;

[0044] Fig.13 and 14 0.5 M compound 5 in H 2 The charge-discharge cycle test results in O solution;

[0045] Fig.15 Schematic diagram of a flow battery device. DETAILED DESCRIPTION

[0046] After long-term and in-depth research, the inventors have developed a hexaazanaphthalene multi-electron compound that can be used as an energy storage material for aqueous liquid flow batteries. The preparation method of the compound is simple, and the prepared battery energy storage material has good cycle stability and energy efficiency. Based on the above findings, the inventors have completed the present invention.

[0047] the term

[0048] In the present invention, the halogen is F, Cl, Br or I.

[0049] In the present invention, the term "C1-C10" refers to having 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 carbon atoms, "C3-C6" refers to having 3, 4, 5 or 6 carbon atoms, and so on.

[0050] In the present invention, the term "alkyl" refers to a saturated linear or branched hydrocarbon moiety. For example, the term "C1-C10 alkyl" refers to a straight or branched alkyl group having 1 to 10 carbon atoms, including but not limited to methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl and hexyl, etc.; preferably ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl and tert-butyl.

[0051] In the present invention, the term "aryl" or "aromatic ring" refers to a hydrocarbon group moiety containing one or more aromatic rings. Examples of aryl include, but are not limited to, phenyl (Ph), naphthyl, pyrenyl, fluorenyl, anthryl, and phenanthryl.

[0052] In the present invention, the term "heteroaryl" refers to a moiety containing one or more aromatic rings having at least one heteroatom (such as N, O, or S). Examples of heteroaryl include furyl, pyrrolyl, thienyl, oxazolyl, imidazolyl, thiazolyl, pyridyl, pyrimidinyl, quinazolinyl, quinolinyl, isoquinolinyl, indolyl, and the like.

[0053] Flow battery

[0054] In a flow battery, the positive and negative electrolyte solutions are respectively stored in external storage tanks and are transferred to the stack by a peristaltic pump. The active materials undergo redox reactions on the electrode surface to achieve energy storage and release. Compared with traditional chemical batteries such as lithium-ion batteries, flow batteries have the advantage that energy and power are independent of each other, that is, the energy magnitude depends on the concentration and volume of the energy storage material, while the power magnitude depends on the electrode area. When the energy storage scale is larger, the cost of this technology is closer to the cost of the energy storage material. Therefore, although lithium-ion batteries have a higher energy density, flow batteries are more suitable for large-scale energy storage power stations. According to the solvent category of the electrolyte used, flow batteries are divided into aqueous flow batteries and non-aqueous (organic solvent) flow batteries.

[0055] Aqueous flow batteries are divided into aqueous inorganic flow batteries and aqueous organic flow batteries according to whether the energy storage material used is inorganic or organic. Currently, the most studied and widely used energy storage materials are all inorganic materials. However, the high cost, limited resources, easy formation of dendrites during use, and slow electrochemical reaction rate of inorganic materials limit the large-scale application of inorganic flow batteries. Using organic substances as energy storage materials, their sources are more extensive than the limited metals stored in the earth's crust, the use cost is lower, and it can reduce the environmental pollution caused by heavy metals. Compared with inorganic materials, organic materials have the advantages of light weight, low cost, ductility, and plasticity; the electrochemical reaction rate of organic materials is relatively fast, usually 1-2 orders of magnitude higher than that of inorganic metals, without the need to use catalysts, and dendrites will not be formed to damage the diaphragm; at the same time, synthetic chemists can modify, transform, and functionalize them at the molecular level, and optimize the solubility and redox potential of organic materials by introducing functional groups, thereby adjusting the energy density and open circuit voltage of the battery. Therefore, studying the structural characteristics, electrochemical characteristics, and possible degradation mechanisms of organic energy storage materials to improve the performance, energy density, and lifespan of aqueous organic flow batteries while reducing their cost is of great significance for promoting the application of flow batteries in the energy storage field, reducing environmental pollution and energy waste, and meeting the demand for electric energy in human production activities.

[0056] Flow battery energy storage materials

[0057] The present invention provides a compound that can be used as an organic energy storage material for an aqueous liquid flow battery, wherein the compound has the following structure:

[0058]

[0059] Wherein, Y and Z are each independently selected from the following group: N, CH;

[0060] m is selected from the group consisting of 0, 1, 2 or 3;

[0061] R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 Each is independently selected from the following group: H, halogen, substituted or unsubstituted C1-C10 alkyl, cycloalkyl, heterocycloalkyl, substituted or unsubstituted C6-C10 aryl, hydroxyl, thiol group, amine group, carboxyl group, phosphate group, sulfonic acid group, or the following water-soluble groups:

[0062] Where n is 1, 2, 3, 4, 5, 6, 7, 8; and R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 At least one of them is the water-soluble group; preferably at least three of them are the water-soluble groups;

[0063] A is O, S or a chemical bond; R 0 Selected from the following group: -COOX, -SO 3 X, -PO 3 X, -NH 2 ·HQ, -NHCH 3 ·HQ, -N(CH 3 ) 2 ·HQ, -N + (CH 3 ) 3 M- ; wherein X is selected from the following group: H + NH 4 + , Li + 、Na + , K + Mg 2+ 、Al 3+ , Ca 2+ ;M - Select from the following group: F - , Cl - Br - ,I - OH - ,OAc - ,OTf - ,OTs - 、SO 4 2- 、SO 3 2- ,PO 4 3- , HPO 4 2- , H 2 PO 4 - 、NO 2 - 、NO 3 - , CO 3 2- , HCO 3 - , ClO 4 - , ClO 3 - , ClO 2 - , ClO - , CN - etc.; Q is selected from the following group: Cl - , SO 4 2- , Y is selected from the group consisting of O, NH, NMe, CH 2 ;

[0064] R p , R q Each is independently selected from the following group: H, substituted or unsubstituted C1-C10 alkyl, cycloalkyl, heterocycloalkyl, or substituted or unsubstituted C6-C10 aryl;

[0065] The substitution refers to that one or more hydrogen atoms on the group are replaced by a substituent selected from the following group: halogen, C1-C6 alkyl, C6-C10 aryl, hydroxyl, thiol group, amine group, carboxyl group, phosphate group, sulfonic acid group.

[0066] In the present invention, preferred compounds have a structure selected from the following group:

[0067]

[0068] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples without specifying specific conditions are usually based on conventional conditions or the conditions recommended by the manufacturer. Unless otherwise stated, percentages and parts are calculated by weight.

[0069] Example 1 (Synthesis of Compound 1)

[0070]

[0071] Synthesis of compound C:

[0072] In a 350 mL pressure bottle, add hexaketone cyclohexane octahydrate A (0.949 g, 3.04 mmol, 1.0 equiv), compound B (3 g, 9.73 mmol, 3.2 equiv), acetic acid (40 mL) and ethanol (40 mL). Heat at 120 ° C overnight. After the reaction is completed, cool to room temperature, extract with dichloromethane and water, adjust the organic phase to neutral with saturated sodium bicarbonate solution, concentrate, column chromatography, and use DCM: EA = 10: 1-5: 1 to obtain compound C (yellow solid, 1.61 g, yield 54%).

[0073] Synthesis of compound 1:

[0074] Compound C (1.61 g, 1.64 mmol, 1.0 equiv), tetrahydrofuran (50 mL), acetonitrile (20 mL), potassium hydroxide (2.0 g, 32.72 mmol, 20 equiv), and water (20 mL) were added to a 250 mL round-bottom flask and reacted for 8 hours at room temperature. The mixture was then concentrated and 6 M HCl was added dropwise to adjust the pH of the system to 1-2 to obtain a solid turbid liquid. The solid was filtered, washed with deionized water, and dried to obtain compound 1 (yellow solid, 1.26 g, yield 94%). Compound 1: 1 H NMR (500 MHz, DMSO-d 6 )δ12.38(s,6H),8.18(s,6H),3.18(t,J=10.0Hz,12H),2.85(t,J=10.0Hz,12H).

[0075] Example 2 (Synthesis of Compound 2 and Its Isomers)

[0076]

[0077] Synthesis of compound E and its isomers:

[0078] In a 120 mL pressure bottle, add hexaketone cyclohexane octahydrate A (2.25 g, 7.19 mmol, 1.0 equiv), compound D (7 g, 23 mmol, 3.2 equiv), acetic acid (35 mL) and ethanol (35 mL). Heat at 120 ° C overnight. After the reaction is completed, cool to room temperature, extract with dichloromethane and water, adjust the organic phase to neutral with saturated sodium bicarbonate solution, concentrate, column chromatography, and use DCM: EA = 10: 1-5: 1 to obtain a mixture of compound E and its isomers (yellow solid, 5.63 g, yield 81%).

[0079] Synthesis of compound F and its isomers:

[0080] Compound E (5.63 g, 5.79 mmol), palladium / carbon (0.56 g, 0.1 equiv), and 60 mL of ethyl acetate were added to a 100 mL polytetrafluoroethylene bottle, and reacted overnight at 85° C. under a hydrogen atmosphere (50 bar). After the reaction, the room temperature was cooled, hydrogen was released, and the mixture was filtered through diatomaceous earth and concentrated to obtain a mixture of compound F and its isomers (yellow solid, 3.4 g, yield 60%).

[0081] Synthesis of compound 2 and its isomers:

[0082] Compound F (3.4 g, 3.49 mmol, 1.0 equiv), tetrahydrofuran (50 mL), acetonitrile (20 mL), potassium hydroxide (4.3 g, 69.8 mmol, 20 equiv), and water (20 mL) were added to a 250 mL round-bottom flask and reacted for 8 hours at room temperature. The mixture was then concentrated and 6 M HCl was added dropwise to adjust the pH of the system to 1-2 to obtain a solid turbid liquid. The solid was filtered, washed with deionized water, and dried to obtain a mixture of compound 2 and its isomers (yellow solid, 2.62 g, yield 92%). Compound 2 and its isomers: 1 H NMR (500 MHz, DMSO-d 6 )δ8.04(d,J=20.0Hz,3H),7.84(d,J=15.0Hz,3H),3.16(t,J=5.0Hz,8H),3.01(t,J=5.0Hz,8H),2.79(t,J=15.0Hz,8H).

[0083] Example 3 (Synthesis of Compound 3-6)

[0084]

[0085] Synthesis of compound H and its isomers:

[0086] In a 120 mL pressure bottle, add hexaketone cyclohexane octahydrate A (2.37 g, 7.6 mmol, 1.0 equiv), compound G (5.79 g, 24.32 mmol, 3.2 equiv), and acetic acid (40 mL). Heat at 120 ° C overnight. After the reaction is completed, cool to room temperature, extract with dichloromethane and water, adjust the organic phase to neutral with saturated sodium bicarbonate solution, concentrate, column chromatography, and use DCM: EA = 1: 1 to obtain a mixture of compound H and its isomers (as a yellow solid, 3.99 g, yield 68%).

[0087] Synthesis of compound 3 and its isomers:

[0088] Compound H (3.99 g, 5.16 mmol, 1.0 equiv), tetrahydrofuran (50 mL), acetonitrile (20 mL), potassium hydroxide (3.21 g, 51.6 mmol, 10 equiv), and water (20 mL) were added to a 250 mL round-bottom flask and reacted for 8 hours at room temperature. After concentration, 6 M HCl was added dropwise to adjust the pH of the system to 1-2 to obtain a solid turbid liquid, which was filtered, washed with deionized water, and dried to obtain a mixture of compound 3 and its isomers (yellow solid, 2.88 g, yield 81%). Compound 3 and its isomers: 1 H NMR (500 MHz, DMSO-d 6 )δ7.85(d,J=60.0Hz,3H),7.42-7.48(m,3H),7.03(d,J=155.0Hz,3H),4.09(d,J=80.0Hz,6H),2.52(d,J=20.0Hz,6H),2.08(s,6H).

[0089] Synthesis of compound 4 and its isomers:

[0090]

[0091] In a 50 mL reaction, hexaketone cyclohexane octahydrate A (0.377 g, 1.2 mmol, 1.0 equiv), compound I (1.11 g, 3.84 mmol, 3.2 equiv), and acetic acid (10 mL) were added. The reaction was allowed to proceed overnight at room temperature. After the reaction was completed, ethyl acetate was added to precipitate a solid, which was filtered and dried. The solid was then purified by a reverse column to obtain a mixture of compound 4 and its isomers (yellow solid, 3.99 g). Compound 4 and its isomers: 1 H NMR (500 MHz, D 2O) δ7.17(d,J=5.0Hz,3H),6.60(d,J=5.0Hz,3H),6.54(dd,J=10.0,5.0Hz,3H),4.12(t,J=5.0Hz,6H),3.05(d,J=5.0Hz,6H),2.19-2.14(m,6H).

[0092] Synthesis of compound 5 and its isomers:

[0093]

[0094] Synthesis of compound K and its isomers:

[0095] In a 120 mL pressure bottle, add hexaketone cyclohexane octahydrate A (4.46 g, 14.3 mmol, 1.0 equiv), compound J (9.6 g, 45.7 mmol, 3.2 equiv), and acetic acid (50 mL). Heat at 120 ° C overnight. After the reaction is completed, cool to room temperature, extract with dichloromethane and water, adjust the organic phase to neutral with saturated sodium bicarbonate solution, concentrate, column chromatography, and use DCM: EA = 1: 1 to obtain a mixture of compound K and its isomers (yellow solid, 8.88 g, yield 90%).

[0096] Synthesis of compound 5 and its isomers:

[0097] Compound K (8.88 g, 12.86 mmol, 1.0 equiv), tetrahydrofuran (50 mL), acetonitrile (20 mL), potassium hydroxide (8.0 g, 128.6 mmol, 10 equiv), and water (20 mL) were added to a 250 mL round-bottom flask and reacted for 8 hours at room temperature. The mixture was then concentrated and 6 M HCl was added dropwise to adjust the pH of the system to 1-2 to obtain a solid turbid liquid, which was filtered, washed with deionized water, and dried to obtain a mixture of compound 5 and its isomers (yellow solid, 5.17 g, yield 90%). Compound 5: 1 H NMR (500 MHz, DMSO-d 6 )δ13.41(s,3H),8.21-8.10(m,3H),7.66-7.37(m,6H),5.29-5.20(m,3H),1.75-1.72(m,9H).

[0098] Synthesis of compound 6 and its isomers:

[0099]

[0100] In a 45mL pressure bottle, add hexaketone cyclohexane octahydrate A (0.13g, 1mmol, 1.0equiv), compound L (0.999g, 3.2mmol, 3.2equiv), and acetic acid (10mL). Heat at 120°C overnight. After the reaction is completed, cool to room temperature, add ethyl acetate, wash with water and dry, and then separate and purify by reverse column chromatography to obtain a mixture of compound 6 and its isomers (black solid, 0.89g, yield 89%). Compound 6: 1 H NMR (500 MHz, DMSO-d 6 )δ12.14(s,6H),7.51(s,6H),4.29(s,12H),2.52(t,J=10.0Hz,12H),2.12(t,J=5.0Hz,12H).

[0101] Test examples (cyclic voltammetry test, battery cycle test)

[0102] Test Example 1 Cyclic Voltammetry Test (Compound 1)

[0103] The cyclic voltammetry test uses a three-electrode system. The working electrode is a 2mm gold disk electrode, the reference electrode is aqueous Ag / AgCl, and the counter electrode is a platinum sheet electrode. The voltage scanning range during the test is: -1.3V~-0.4V, and the scanning rate is 20mV / s.

[0104] Cyclic voltammogram of test compound 1 in 1M KOH solution, as shown in Figure 1 The results show that the compound can exhibit good redox performance under 1M KOH conditions, with two pairs of reversible redox peaks. The first pair of E 1 / 2 =-1.02V (vs Ag / AgCl), ΔE = 330mV; the second pair E 1 / 2 =-0.787V (vs Ag / AgCl), ΔE=215mV.

[0105] Test Example 2 Cyclic Voltammetry Test (Compound 2 and Its Isomers)

[0106] The cyclic voltammetry test uses a three-electrode system. The working electrode is a 2mm gold disk electrode, the reference electrode is aqueous Ag / AgCl, and the counter electrode is a platinum sheet electrode. The voltage scanning range during the test is: -1.3V~-0.4V, and the scanning rate is 20mV / s.

[0107] Cyclic voltammograms of test compound 2 and its isomers in 1 M KOH solution, as shown in Figure 2 The results show that the compound can exhibit good redox performance under 1M KOH conditions, with two pairs of reversible redox peaks. The first pair of E 1 / 2=-1.03V (vs Ag / AgCl), ΔE = 420mV; the second pair E 1 / 2 =-0.68V (vs Ag / AgCl), ΔE=390mV.

[0108] Test Example 3 Cyclic Voltammetry Test (Compound 3 and Its Isomers)

[0109] The cyclic voltammetry test uses a three-electrode system. The working electrode is a 2mm gold disk electrode, the reference electrode is aqueous Ag / AgCl, and the counter electrode is a platinum sheet electrode. The voltage scanning range during the test is: -1.3V~0.6V, and the scanning rate is 20mV / s.

[0110] Cyclic voltammograms of test compound 3 and its isomers in 1 M NaOH solution, as shown in Figure 3 The results show that the compound can exhibit good redox performance under 1M NaOH conditions. It has two pairs of reversible redox peaks. The first pair is E 1 / 2 =-1.15V (vs Ag / AgCl), ΔE = 115mV; the second pair E 1 / 2 =-0.765V (vs Ag / AgCl), ΔE=70mV.

[0111] Test Example 4 Cyclic Voltammetry Test (Compound 4 and Its Isomers)

[0112] The cyclic voltammetry test uses a three-electrode system. The working electrode is a 2mm gold disk electrode, the reference electrode is aqueous Ag / AgCl, and the counter electrode is a platinum sheet electrode. The voltage scanning range during the test is: -1.0V~0V, and the scanning rate is 20mV / s.

[0113] Cyclic voltammograms of test compound 4 and its isomers in 1 M KCl solution, as shown in Figure 4 The results show that the compound can exhibit good redox performance under 1M KCl conditions. It has two pairs of reversible redox peaks. The first pair is E 1 / 2 =-0.62V (vs Ag / AgCl), ΔE = 129mV; the second pair E 1 / 2 =-0.37V (vs Ag / AgCl), ΔE=39mV.

[0114] Test Example 5 Cyclic Voltammetry Test (Compound 5 and Its Isomers)

[0115] The cyclic voltammetry test uses a three-electrode system. The working electrode is a 2mm gold disk electrode, the reference electrode is aqueous Ag / AgCl, and the counter electrode is a platinum sheet electrode. The voltage scanning range during the test is: -1.3V~-0.6V, and the scanning rate is 20mV / s.

[0116] Cyclic voltammograms of test compound 5 and its isomers in 1 M KOH solution are as follows Figure 5 shown. The results show that the compound can exhibit good redox performance under 1 M KOH conditions. It has two pairs of reversible redox peaks. The first pair has E 1 / 2 = -0.974 V (vs Ag / AgCl), ΔE = 190 mV; the second pair has E 1 / 2 = -0.777 V (vs Ag / AgCl), ΔE = 223 mV.

[0117] Test Example 6 Current Cycling Test (Compound 1)

[0118] The main parameters and schematic diagram of the flow battery device are as shown in Fig.15 . A potentiostat was used to conduct constant current and constant current-constant voltage charge-discharge cycling tests. A battery was assembled with compound 1, using an NC700 cation exchange membrane and ELAT carbon cloth as the electrode materials. The charge-discharge current in the constant current stage was 100 mA, and the current density was 20 mA / cm 2 , and the voltage range in the constant voltage stage was 1.6 V - 0.4 V, with a cut-off current of 20 mA.

[0119] During the battery cycling process, the negative electrode solution was 7.0 mL of 0.1 M compound 1 dissolved in 1 M KOH solution; the positive electrode solution was 60 mL of 0.15 M K 4 Fe(CN) 6 and 0.05 M K 3 Fe(CN) 6 dissolved in 1 M KOH solution.

[0120] The test results of compound 1 in 1 M KOH solution are as shown in Figure 6 and 7 . First, 80 cycles (6.45 days) of constant current cycling tests were carried out, and no capacity loss was observed. Then, constant current-constant voltage charge-discharge tests were continued for a total of 512 cycles (49.6 days). The battery capacity decayed by 0.001% / cycle. The actual capacity utilization in the constant current stage accounted for 85% of the theoretical capacity, and after adding the constant voltage stage, the capacity utilization increased to 94%, and the coulombic efficiency could reach 100%.

[0121] Test Example 7 High-Concentration Current Cycling Test (Compound 1)

[0122] The main parameters and schematic diagram of the flow battery device are as shown in Fig.15 . A potentiostat was used to conduct constant current-constant voltage charge-discharge cycling tests. A battery was assembled with compound 1, using an NC 700 cation exchange membrane and ELAT carbon cloth as the electrode materials. The charge-discharge current in the constant current stage was 100 mA, and the current density was 20 mA / cm 2,The voltage range in the constant voltage stage is 1.7V-0.4V, and the cut-off current is 20mA.

[0123] During the battery cycle, the negative electrode solution was 7.0 mL of 0.4 M potassium salt of compound 1 dissolved in 1 M KOH solution; the positive electrode solution was 80 mL of 0.3 M KOH. 4 Fe(CN) 6 and 0.4MK 3 Fe(CN) 6 Dissolve in 1M KOH solution.

[0124] The test results of compound 1 in 1M KOH solution are as follows Figure 8 and 9 The constant current and constant voltage charge and discharge test lasted 237 cycles, the battery capacity decayed by 0.001% / cycle, the actual capacity accounted for 78% of the theoretical capacity, and the coulomb efficiency could reach 100%.

[0125] Test Example 8 Current Cycling Test (Compound 5)

[0126] The constant current and constant current constant voltage charge and discharge cycle tests were performed using an electrochemical workstation. The battery was assembled with compound 5, using NC700 cation exchange membrane and ELAT carbon cloth as electrode materials. The charge and discharge current in the constant current stage was 100 mA, and the current density was 20 mA / cm 2 ,The voltage range in the constant voltage stage is 1.6V-0.4V, and the cut-off current is 20mA.

[0127] During the battery cycle, the negative electrode solution was 7.0 mL of 0.1 M compound 5 dissolved in 1 M KOH solution; the positive electrode solution was 50 mL of 0.15 M KOH solution. 4 Fe(CN) 6 and 0.05MK 3 Fe(CN) 6 Dissolve in 1M KOH solution.

[0128] The test results of compound 5 in 1M KOH solution are as follows Fig.11 and 12 As shown. First, a constant current cycle test was performed for 43 cycles (3.7 days), and no obvious capacity loss was observed. Then, a constant current and constant voltage charge and discharge test was performed for a total of 307 cycles (26.4 days). The battery capacity decayed by 0.007% / cycle. The actual capacity in the constant current stage accounted for 93% of the theoretical capacity. After the constant voltage was added, the capacity utilization rate increased to 94%, and the coulomb efficiency could reach 100%.

[0129] Test Example 9 High Concentration Current Cycling Test (Compound 5)

[0130] The main parameters and schematic diagram of the flow battery device are as follows: Fig.15As shown in . The constant current and constant voltage charge-discharge cycle test was carried out using an electrochemical workstation. A battery was assembled with Compound 5, using an NC 700 cation exchange membrane and carbon cloth as the electrode material. The charge-discharge current in the constant current stage was 100 mA, and the current density was 20 mA / cm 2 , and the voltage range in the constant voltage stage was 1.6 V - 0.4 V, with a cut-off current of 20 mA.

[0131] During the battery cycle, the negative electrode solution was 5.0 mL of 0.5 M potassium salt of Compound 5 dissolved in water; the positive electrode solution was 20 mL of 0.4 M K 4 Fe(CN) 6 , 0.6 M Na 4 Fe(CN) 6 and 0.4 M K 3 Fe(CN) 6 dissolved in water.

[0132] The test results of the potassium salt of Compound 5 in water are as shown in Fig.13 and 14 shown. The constant current and constant voltage charge-discharge test lasted for 81 days. The battery capacity decayed at a rate of 0.095% per day. The actual capacity utilization accounted for 85% of the theoretical capacity, and the coulombic efficiency could reach 100%.

[0133] All documents mentioned in the present invention are cited herein by reference as if each document was individually cited as a reference. In addition, it should be understood that after reading the above teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

Claims

1. A compound represented by the following formula: in, Y and Z are each independently selected from the group consisting of N, CH; m is selected from the group consisting of 0, 1, 2 or 3; R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 Each is independently selected from the following group: H, halogen, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C2-C10 alkenyl, cycloalkyl, heterocycloalkyl, substituted or unsubstituted C6-C10 aryl, hydroxyl, thiol, amine, carboxyl, phosphate, sulfonic acid, or the following water-soluble groups: Where n is 1, 2, 3, 4, 5, 6, 7, 8; and R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 At least one of them is the water-soluble group; preferably at least three of them are the water-soluble groups; A is O, S or a chemical bond; R 0 Selected from the following group: -COOX, -SO3X, -PO3X, -NH2·HQ, -NHCH3·HQ, -N(CH3)2·HQ, -N + (CH3)3M - ; wherein X is selected from the following group: H + NH4 + , Li + 、Na + , K + Mg 2+ 、Al 3+ , Ca 2+ ;M - Select from the following group: F - , Cl - Br - ,I - OH - ,OAc - ,OTf - ,OTs - 、SO4 2- 、SO3 2- PO4 3- 、HPO4 2- 、H2PO4 - 、NO2 - 、NO3 - 、CO3 2- 、HCO3 - 、ClO4 - 、ClO3 - 、ClO2 - , ClO - , CN - etc.; Q is selected from the following group: Cl - , SO4 2- , Y is selected from the group consisting of O, NH, NMe, CH2; R p , R q Each is independently selected from the following group: H, substituted or unsubstituted C1-C10 alkyl, cycloalkyl, heterocycloalkyl, or substituted or unsubstituted C6-C10 aryl; The substitution refers to that one or more hydrogen atoms on the group are replaced by a substituent selected from the following group: halogen, C1-C6 alkyl, C6-C10 aryl, hydroxyl, thiol group, amine group, carboxyl group, phosphate group, sulfonic acid group.

2. The compound as claimed in claim 1, characterized in that The compound is selected from the following group: wherein Y and Z are each independently N.

3. The compound as claimed in claim 1, characterized in that The R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 Each is independently selected from the following group: H, halogen, substituted or unsubstituted C1-C10 alkyl, cycloalkyl, heterocycloalkyl, hydroxyl, thiol, amine, carboxyl, phosphoric acid, sulfonic acid, or the following water-soluble groups: Wherein, n is 1, 2, 3, 4, 5, 6, 7, 8; A is O, S or a chemical bond; R 0 Selected from the following group: -COOX, -SO3X, -PO3X, -NH2·HQ, -NHCH3·HQ, -N(CH3)2·HQ, -N + (CH3)3M - ; wherein X is selected from the following group: H + NH4 + , Li + 、Na + , K + Mg 2+ 、Al 3+ , Ca 2+ ;M - Select from the following group: F - , Cl - Br - ,I - OH - ,OAc - ,OTf - ,OTs - 、SO4 2- 、SO3 2- PO4 3- 、HPO4 2- 、H2PO4 - 、NO2 - 、NO3 - 、CO3 2- 、HCO3 - 、ClO4 - 、ClO3 - 、ClO2 - , ClO - , CN - etc.; Q is selected from the following group: Cl - , SO4 2- , Y is selected from the group consisting of O, NH, NMe, CH2; R p , R q Each is independently selected from the following group: H, substituted or unsubstituted C1-C10 alkyl, cycloalkyl, heterocycloalkyl, or substituted or unsubstituted C6-C10 aryl; The substitution refers to that one or more hydrogen atoms on the group are replaced by a substituent selected from the following group: halogen, C1-C6 alkyl, C6-C10 aryl, hydroxyl, thiol group, amine group, carboxyl group, phosphate group, sulfonic acid group.

4. The compound as claimed in claim 1, characterized in that The R 1 , R 4 , R 5 , R 8 , R 9 , R 12 Each independently is H; R 2 , R 3 , R 6 , R 7 , R 10 and R 11 Each independently selected from the following group: substituted or unsubstituted C1-C10 alkyl, hydroxyl, thiol, amine, carboxyl, phosphoric acid, sulfonic acid, or the following water-soluble groups Wherein, n is 1, 2, 3, 4, 5, 6, 7, 8; A is O, S or a chemical bond; R 0 Selected from the following group: -COOX, -SO3X, -PO3X, -NH2·HQ, -NHCH3·HQ, -N(CH3)2·HQ, -N + (CH3)3M - ; wherein X is selected from the following group: H + NH4 + , Li + 、Na + , K + Mg 2+ 、Al 3+ , Ca 2+ ;M - Select from the following group: F - , Cl - Br - ,I - OH - ,OAc - ,OTf - ,OTs - 、SO4 2- 、SO3 2- PO4 3- 、HPO4 2- 、H2PO4 - 、NO2 - 、NO3 - 、CO3 2- 、HCO3 - 、ClO4 - 、ClO3 - 、ClO2 - , ClO - , CN - ; Q is selected from the following group: Cl - , SO4 2- ; Y is selected from the group consisting of O, NH, NMe, CH2.

5. A compound as claimed in claim 1, or a salt thereof which optionally loses an H atom, or a salt thereof with a charge-balancing ion, characterized in that The compound has a structure shown in the following formula:

6. A compound as claimed in claim 1, or a salt thereof which optionally loses an H atom, or a salt thereof with a charge-balancing ion, characterized in that The compound is selected from the following group:

7. A method for preparing a compound as claimed in claim 1, or a compound optionally losing an H atom thereof, or a salt thereof with a charge-balancing ion, characterized in that: The method comprises the steps of: In the presence of a condensing agent, (Ia-1) and (Ia-2) are reacted to obtain a compound of formula (Ia); wherein R 1 , R 4 , R 5 , R 8 , R 9 , R 12 Each is independently H; preferably, the reaction is carried out in an ethanol solution; more preferably, the condensation agent is acetic acid.

8. A liquid flow battery energy storage material, characterized in that: The liquid flow battery energy storage material is prepared using the compound described in any one of claims 1 to 6 as an active ingredient.

9. A liquid flow battery, characterized in that: The liquid flow battery comprises the compound as described in any one of claims 1 to 5 as an energy storage material.

10. The flow battery according to claim 9, characterized in that In the liquid flow battery, the compound described in any one of claims 1 to 6 is used as the negative electrode or positive electrode solution.

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