A polymeric flow battery positive electrode material and a method of making the same

Abstract

This invention discloses a polymeric flow battery cathode material and its preparation method. The polymeric flow battery cathode material is a TEMPO polymer, which includes the structure shown in Formula I, as well as the structures shown in Formula II and / or Formula III. By using TEMPO polymer as the cathode material and methyl viologen or its derivatives as the anode material, this invention yields a polymeric flow battery with outstanding advantages such as high stability, good safety, flexible configuration, fast response, environmental friendliness, high capacity, and stable charge-discharge performance, providing strong support for the application of large-scale energy storage technology.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials, specifically relating to a polymeric flow battery cathode material and its preparation method. Background Technology

[0002] Flow batteries possess advantages such as high safety, long cycle life, recyclable electrolyte, high cost-effectiveness over their lifecycle, and environmental friendliness, making them one of the preferred technologies for large-scale energy storage with broad application prospects. Unlike conventional battery technology, the electrodes in flow batteries only provide a reaction interface for the active materials and do not undergo electrochemical reactions themselves. Furthermore, the positive and negative electrode active materials are typically stored in ionic form in the electrolyte and placed in separate positive and negative electrode storage tanks. During charging and discharging, the electrolyte is circulated into the battery or stack via a pump, where redox reactions occur on the electrode surfaces to achieve the interconversion of chemical energy and electrical energy.

[0003] Vanadium redox flow batteries are among the most mature and commercially viable flow battery technologies currently available, and are widely used in large-scale energy storage. However, vanadium redox flow battery energy storage technology is relatively expensive, and the pentavalent vanadium in the cathode of vanadium redox flow batteries is prone to precipitation at temperatures exceeding 45°C, forming the highly toxic vanadium pentoxide, which is not only harmful to the entire flow battery system but also poses a threat to the environment.

[0004] TEMPO-based flow batteries, as a novel type of aqueous flow battery, have attracted much attention due to their advantages such as low cost, high voltage, good reversibility, and tunable structure. However, water-soluble TEMPO molecules are prone to disproportionation and ring-opening side reactions during charge and discharge, leading to molecular degradation or deactivation, thus affecting battery life. For example, patent document CN114824398B discloses a PAA-grafted TEMPO polymer with a linear structure, but its solubility in water greatly limits its electrochemical performance.

[0005] Therefore, finding a flow battery cathode material that is highly soluble in water and does not easily undergo side reactions such as disproportionation and ring opening through molecular structure design is an urgent problem to be solved. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention provides a polymeric flow battery cathode material and its preparation method.

[0007] In a first aspect, the present invention provides a TEMPO polymer comprising the structure shown in Formula I, and the structures shown in Formula II and / or Formula III:

[0008]

[0009] Among them, M1, M2, and M3 are cations, which are independently selected from: K + Na + NH4 + ;

[0010] X is selected from: -O-, -NH-;

[0011] R is selected from: -H, -L-(C1-C) 10 alkyl);

[0012] L is selected from: single bond, C2-C 10 alkenyl, C2-C 10 Alkyne group, -(C0-C6 alkylene group)-(C3-C6 alkylene group) 10 Cycloalkylene)-, -(C0-C6 alkylene)-(C6-C 10 (arylene)-, -(C0-C6 alkylene)-(C3-C 10 -Hypercyclic groups: -O-, -S-, -C(O)-, -C(S)-, -C(O)O-, -C(O)N(R) A )-, -OC(O)-, -OC(O)O-, -OC(O)N(R A )-、-N(R A )-、-N(R A )C(O)-、-N(R A )C(O)O-、-N(R A )C(O)N(R B )-;

[0013] R A R B Independently selected from: H, halogen, cyano, nitro, azide, C1-C 10 Alkyl, C2-C 10 alkenyl, C2-C 10 alkynyl, -(C0-C6 alkylene)-(C3-C 10 cycloalkyl), -(C0-C6 alkylene)-(C6-C 10 aryl), -(C0-C6 alkylene)-(3-10 membered heterocyclic), C1-C 10 Haloalkyl, -O(C) 0-10 alkyl), -CO(C) 0-10 Alkyl), -COO(C 0-10 Alkyl), -CON(C) 0-10 Alkyl)(C 0-10 Alkyl), -OCO(C 0-10 Alkyl), -OCOO(C 0-10 Alkyl), -OCON(C) 0-10alkyl), -N(C) 0-10 Alkyl)(C 0-10 alkyl), -N(C) 0-10 Alkyl)CO(C 0-10 alkyl), -N(C) 0-10 Alkyl)COO(C 0-10 alkyl), -N(C) 0-10 Alkyl)CON(C 0-10 alkyl);

[0014] n, m, and o are the aggregation degrees of the units, which are independent integers from 1 to 20, specifically 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20.

[0015] Further, the molecular weight of the TEMPO polymer is 1000-50000, specifically such as 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000, 11000, 12000, 13000, 14000, 15000, 16000, 17000, 18000, 19000, 20000, 22000, 24000, 26000, 28000, 30000, 35000, 40000, 45000, 50000, preferably 8000-11000.

[0016] Furthermore, L is selected from: single bond, -(C0-C6 alkylene)-(C3-C6 alkylene)-(C3-C6 alkylene)-(C6 ... 10 Cycloalkylene)-, -(C0-C6 alkylene)-(C6-C 10 (Aspartic)-.

[0017] Furthermore, L is selected from: single bond,

[0018] In some embodiments of the present invention, L represents a single bond.

[0019] Furthermore, R is selected from: H,

[0020] In some embodiments of the present invention, R is selected from: H,

[0021] Furthermore, the TEMPO polymer is prepared by polymerization and oxidation reactions of compound A with compound B and / or compound C.

[0022] Furthermore, compound A has the structure shown in Formula IV:

[0023] Furthermore, compound B has the structure shown in formula V:

[0024] Furthermore, compound C has the structure shown in formula VI:

[0025] In some embodiments of the present invention, compound A has the following structure:

[0026]

[0027] Furthermore, compound B has the following structure:

[0028]

[0029]

[0030] In some embodiments of the present invention, compound B has the following structure:

[0031]

[0032] In some embodiments of the present invention, compound C has the following structure:

[0033]

[0034] Furthermore, the TEMPO polymer is a random copolymer with a structure that is any combination of the structure shown in Formula I and the structures shown in Formula II and / or Formula III.

[0035] In some embodiments of the present invention, the TEMPO polymer comprises the structures shown in Formula I and Formula II, which are obtained by polymerization and oxidation reactions of compound A and compound B. For example, the TEMPO polymer has the following structure:

[0036]

[0037] In some embodiments of the present invention, the TEMPO polymer comprises the structures shown in Formulas I and III, which are obtained by polymerization and oxidation reactions of compound A and compound C. For example, the TEMPO polymer has the following structure:

[0038]

[0039] In some embodiments of the present invention, the TEMPO polymer comprises the structures shown in Formulas I, II, and III, and is prepared by polymerization and oxidation reactions of compound A with compounds B and C. For example, the TEMPO polymer has the following structure:

[0040]

[0041]

[0042] A second aspect of the present invention provides a method for preparing the TEMPO polymer described in the first aspect of the present invention, the method comprising dissolving compound A and compound B and / or compound C in a solvent, adding an initiator to carry out a polymerization reaction to obtain an intermediate product, and adding an oxidant to carry out an oxidation reaction to obtain the TEMPO polymer.

[0043] Furthermore, the solvent is water or an acidic solution (such as aqueous HCl solution or aqueous HBr solution).

[0044] In some embodiments of the present invention, the solvent is water.

[0045] Furthermore, the initiator is selected from: azo initiators and peroxide initiators.

[0046] Furthermore, the azo initiator is selected from: azobisisobutyramidine hydrochloride, 4,4'-azobis(4-cyanopentaic acid), azobisisobutyramidazole hydrochloride, azoisobutyramidoformamide, dimethyl azobisisobutyrate, and azobisisopropylimidazoline hydrochloride.

[0047] Further, the peroxide initiator is selected from: benzoyl peroxide, lauroyl peroxide, tert-butyl peroxypentanoate, tert-pentyl peroxypentanoate, tert-butyl peroxyacetate, tert-butyl peroxyneodecanate, tert-butyl peroxyisononanoate, tert-pentyl peroxybenzoate, tert-butyl peroxy-2-ethylhexyl carbonate, bis(4-tert-butylcyclohexyl) peroxydicarbonate, tert-butyl peroxy(2-ethylhexanoate), di(2-ethylhexyl) peroxydicarbonate, cumyl peroxyneodecanate, tert-butyl peroxymaleate, hydrogen peroxide, and tert-butyl hydrogen peroxide.

[0048] In some embodiments of the present invention, the initiator is 4,4'-azobis(4-cyanopentaic acid).

[0049] In some embodiments of the present invention, the initiator is tert-butyl hydroperoxide.

[0050] Further, the mass of the initiator is 0.1-5% of the mass of compound A, specifically such as 0.1, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.2, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.2, 2.4, 2.6, 2.8, 3, 3.5, 4, 4.5, 5%, preferably 1-1.5%.

[0051] Furthermore, the molar ratio of compound A to compound B is 1:1-1.5, specifically 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, and more preferably 1:1.

[0052] Furthermore, the molar ratio of compound A to compound C is 1:1-1.5, specifically 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, and more preferably 1:1.

[0053] Furthermore, the polymerization reaction temperature is 0-150℃, preferably 30-150℃, and more preferably 100-130℃.

[0054] Furthermore, the polymerization reaction takes 2-12 hours, more preferably 6-10 hours.

[0055] Furthermore, a chain transfer agent, such as 2-mercaptoethanol, may be added to the polymerization reaction.

[0056] Further, the oxidant is selected from: benzoyl peroxide, lauroyl peroxide, tert-butyl peroxypentanoate, tert-pentyl peroxypentanoate, tert-butyl peroxyacetate, tert-butyl peroxyneodecanate, tert-butyl peroxyisononanoate, tert-pentyl peroxybenzoate, tert-butyl peroxy-2-ethylhexyl carbonate, bis(4-tert-butylcyclohexyl) peroxydicarbonate, tert-butyl peroxy(2-ethylhexanoate), di(2-ethylhexyl) peroxydicarbonate, cumyl peroxyneodecanate, tert-butyl peroxymaleate, hydrogen peroxide, and tert-butyl hydrogen peroxide.

[0057] In some embodiments of the present invention, the oxidant is hydrogen peroxide.

[0058] In some embodiments of the present invention, the oxidant is tert-butyl hydroperoxide.

[0059] Further, the mass of the oxidant is 5-20% of the mass of the intermediate product, specifically such as 5, 6, 7, 7.5, 8, 9, 10, 10.5, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20%, preferably 8-10%.

[0060] Furthermore, a catalyst may be added to the oxidation reaction.

[0061] Furthermore, the catalyst is selected from: phosphomolybdic acid, phosphotungstic acid, sodium molybdate, sodium tungstate, silicomolybdic acid, silicostic acid, molybdenum trioxide, dextrose trioxide, and ethylenediaminetetraacetic acid.

[0062] In some embodiments of the present invention, the catalyst is molybdenum trioxide.

[0063] In some embodiments of the present invention, the catalyst is sodium tungstate.

[0064] In some embodiments of the present invention, the catalyst is phosphotungstic acid.

[0065] Further, the mass of the catalyst is 0.05-5% of the mass of the intermediate product, specifically such as 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3, 3.2, 3.4, 3.6, 3.8, 4, 4.2, 4.4, 4.6, 4.8, 5%, preferably 2-3%.

[0066] Furthermore, the temperature of the oxidation reaction is 0-150°C, preferably 30-150°C, and more preferably 70-90°C.

[0067] Furthermore, the oxidation reaction takes 2-12 hours, more preferably 6-8 hours.

[0068] Furthermore, the preparation method also includes a post-treatment step, which refers to adding sodium sulfite to reduce excess oxidant.

[0069] A third aspect of the present invention provides the application of the TEMPO polymer described in the first aspect of the present invention or the TEMPO polymer prepared by the preparation method described in the second aspect of the present invention as a positive electrode material in a polymeric flow battery.

[0070] In a fourth aspect, the present invention provides a flow battery system comprising a positive electrode reservoir, a negative electrode reservoir, and a flow battery stack; the two ends of the flow battery stack are respectively connected to the positive electrode reservoir and the negative electrode reservoir.

[0071] Furthermore, the positive electrode storage tank and the negative electrode storage tank are storage tanks containing electrolytes. The positive electrode storage tank contains a positive electrode material and a supporting electrolyte, and the negative electrode storage tank contains a negative electrode material and a supporting electrolyte. The positive electrode material and the negative electrode material are directly dissolved or dispersed in a system with water as a solvent in bulk form. The positive electrode material is the TEMPO polymer described in the first aspect of the present invention or the TEMPO polymer prepared by the preparation method described in the second aspect.

[0072] Furthermore, the negative electrode material is methyl viologen and / or a derivative of methyl viologen.

[0073] Further, the concentrations of the positive electrode material and the negative electrode material are 0.05-3 mol / L (e.g., 0.05, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.18, 0.2, 0.22, 0.24, 0.26, 0.28, 0.3, 0.35, 0.4, 0.45, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, 2.5, 3 mol / L), preferably 0.1 mol / L.

[0074] Furthermore, the supporting electrolyte is selected from one or more of NaCl aqueous solution, KCl aqueous solution, Na2SO4 aqueous solution, K2SO4 aqueous solution, MgCl2 aqueous solution, MgSO4 aqueous solution, CaCl2 aqueous solution, and NH4Cl aqueous solution, preferably NaCl aqueous solution or KCl aqueous solution.

[0075] Further, the concentration of the supporting electrolyte is 0.1-8 mol / L (e.g., 0.1, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 2, 2.2, 2.4, 2.6, 2.8, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8 mol / L), preferably 1 mol / L.

[0076] Furthermore, the positive electrode storage tank and the negative electrode storage tank are pressurized sealed containers with a pressure of 0.1-0.5 MPa.

[0077] Furthermore, inert gas (such as argon) is introduced into the positive electrode storage tank and the negative electrode storage tank for purging and pressure maintenance.

[0078] Furthermore, the flow battery stack includes a battery separator that divides the flow battery stack into a positive electrode region and a negative electrode region. The positive electrode region is connected to a positive electrode storage tank, and the negative electrode region is connected to a negative electrode storage tank.

[0079] Furthermore, the positive electrode region is connected to the positive electrode storage tank via a positive electrode circulation pipeline, and the negative electrode region is connected to the negative electrode storage tank via a negative electrode circulation pipeline.

[0080] Furthermore, the battery separator is selected from: cation exchange membrane, anion exchange membrane, selective permeable membrane, and polymer porous membrane.

[0081] Furthermore, the battery separator can allow the supporting electrolyte to pass through while preventing the positive and negative active materials from passing through.

[0082] Furthermore, a positive current collector is installed in the positive electrode region, and a negative current collector is installed in the negative electrode region; the current collector can collect the current generated by the active material of the flow battery stack and conduct it to the external wires.

[0083] Furthermore, the current collector is selected from: conductive metal plate, graphite plate, and carbon-plastic composite plate.

[0084] Furthermore, the conductive metal plate contains at least one metal selected from copper, nickel, and aluminum.

[0085] Furthermore, electrodes are respectively provided in the positive electrode region and the negative electrode region. The electrodes are carbon material electrodes, which are selected from one or more of the following: carbon felt, carbon paper, carbon cloth, carbon black, activated carbon fiber, activated carbon particles, graphene, graphite felt, and glassy carbon materials.

[0086] Furthermore, the electrode is formed as an electrode plate.

[0087] Furthermore, the flow battery system also includes a pump system for delivering the electrolyte.

[0088] Furthermore, the pump set is selected from: peristaltic pump, mechanical pump, and magnetic pump.

[0089] The present invention has the following beneficial effects:

[0090] The TEMPO polymer of this invention can be used as the positive electrode material for flow batteries. This TEMPO polymer is characterized by low cost and ease of synthesis. By using TEMPO polymer as the positive electrode material and methyl viologen or its derivatives as the negative electrode material, this invention yields a polymeric flow battery with outstanding advantages such as high stability, good safety, flexible configuration, fast response, environmental friendliness, high capacity, and stable charge-discharge performance, providing strong support for the application of large-scale energy storage technology. Detailed Implementation

[0091] Unless otherwise defined, all scientific and technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art.

[0092] The term "alkyl" refers to a straight-chain or branched hydrocarbon radical that does not contain unsaturated bonds and is connected to the rest of the molecule by single bonds. Typical alkyl groups contain 1 to 10 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10) carbon atoms, preferably 1 to 6 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, isohexyl, etc. In this invention, CO alkyl refers to H, i.e., C 0-10 Alkyl (or C0-C) 10Alkyl groups include H and C. 1-10 Alkyl (or C1-C) 10 alkyl).

[0093] The term "alkylene" refers to a hydrocarbon group (divalent alkyl) formed by the loss of two hydrogen atoms from an alkane molecule. It can be straight-chain or branched and is connected to the rest of the molecule by a single bond. Typical alkylene groups described herein have 1 to 10 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10) carbon atoms, preferably 1 to 6 carbon atoms, such as methylene (-CH2-), ethylene, propylene, butylene, etc. In this invention, CO alkylene refers to a single bond, i.e., C... 0-10 Alkylene (or C0-C) 10 Alkylenes include single bonds and C bonds. 1-10 Alkylene (or C1-C) 10 (alkylene).

[0094] The term "cycloalkyl" refers to alicyclic hydrocarbons, such as those containing 1 to 4 monocyclic and / or fused rings, containing 3 to 18 carbon atoms, preferably 3 to 10 (e.g., 3, 4, 5, 6, 7, 8, 9, 10) carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, or adamantyl.

[0095] The term "halogen" refers to fluorine, chlorine, bromine, or iodine.

[0096] The term "haloalkyl" refers to a group formed by replacing one or more hydrogen atoms in an alkyl group with a halogen atom (such as fluorine, chlorine, bromine or iodine), such as -CHF2, -CH2F, -CF3, -CH2-CF3, -CH2CH2-CF3, -CH2CH2CH2-CF3.

[0097] The term "aryl" refers to a monocyclic or polycyclic free radical, including polycyclic free radicals containing a monoaryl group and / or a fused aryl group (also referred to herein as "aromatic ring"), such as those containing 1-3 monocyclic or fused rings and 6-18 (e.g., 6, 8, 10, 12, 14, 16, 18) carbon ring atoms, C6-C as described in this invention. 12 The aryl group refers to an aryl group containing 6-12 carbon ring atoms, such as phenyl, naphthyl, biphenyl, indene, etc.

[0098] The term "heterocyclic group" refers to a 3- to 18-membered non-aromatic ring group containing 2 to 17 carbon atoms and 1 to 10 heteroatoms. Heterocyclic groups can be monocyclic, bicyclic, tricyclic, or tetracyclic ring systems, and can include fused, spirocyclic, or bridged ring systems. Heterocyclic groups (also referred to herein as "heterocycles") can be partially saturated (heteroaryl, also referred to herein as "heteroaromatic rings") or fully saturated (heterocyclic alkyl). Suitable heteroaryl groups in the compounds of the present invention contain one, two, or three heteroatoms selected from N, O, S, and P atoms. These heteroaryl groups include, for example, coumarin (including 8-coumarin), quinolinyl (including 8-quinolinyl, isoquinolinyl, pyridinyl, pyrazinyl, pyrazolyl, pyrimidinyl, furanyl, pyrroloyl, thiopheneyl, thiazolyl, isothiazolyl, triazolyl, tetrazolyl, isoxazolyl, oxazolyl, imidazoleyl, indolyl, isoyndolyl, indazoleyl, inazinyl, phthalazinyl, pteridinyl, purinyl, oxadiazolyl, thiadiazolyl, furazolidyl, pyridazinyl, triazinyl, cenolinyl, benzimidazolyl, benzofuranyl, benzofuranyl, benzothiopheneyl, benzothiazolyl, benzooxazolyl, quinazolinyl, quinoxolinyl, naphridinyl, and furanopyridinyl. Suitable heterocyclic alkyl groups in the compounds of the present invention contain one, two, or three heteroatoms selected from N, O, or S atoms. These heterocyclic alkyl groups include, for example, pyrrolidinyl, tetrahydrofuranyl, dihydrofuranyl, tetrahydrothiophenyl, tetrahydrothiophenyl, piperidinyl, morpholinyl, thiomorpholinyl, oxothiohexacyclohexyl, piperazine, aziridine, oxothiohexacyclohexyl, thiohexacyclohexyl, homopiperidinyl, oxopropane, thiopropane, acrylonitrile, oxo-aziridine, diaziridine, etc. Heptyl, triacetyl, 1,2,3,6-tetrahydropyridyl, 2-pyrrolinyl, 3-pyrrolinyl, dihydroindolyl, 2H-pyranyl, 4H-pyranyl, dioxacyclohexyl, 1,3-dioxapentyl, pyrazolinyl, dithiaalkyl, dithiopentyl, dihydropyranyl, dihydrothiophenyl, pyrazolinyl, imidazolinyl, imidazolinyl, 3-azabicyclo[3.1.0]hexyl, 3-azabicyclo[4.1.0]heptyl, 3H-indolyl, and quinazinyl. In this invention, for optionally substituted heterocyclic groups, the substituted position can be any suitable carbon atom or heteroatom, for example, for The substitution position of R can be any suitable carbon or nitrogen atom, and it can be, for example...

[0099] The salt form of the TEMPO polymer of the present invention is a base addition salt. The term "base addition salt" refers to a salt formed with a metal or amine, such as hydroxides of alkali metals and alkaline earth metals, or with an organic amine. Examples of metals used as cations include, but are not limited to, sodium, potassium, magnesium, and calcium. Examples of suitable amines include, but are not limited to, N,N′-dibenzylethylenediamine, chloroprocaine, choline, diethanolamine, ethylenediamine (1,2-diaminoethane), N-methylglucosamine, and procaine. The base addition salt can be prepared by contacting the free acid form with a sufficient amount of the desired base in a conventional manner to form the salt. The free acid form can be regenerated by contacting the salt form with an acid, and the free acid can be separated in a conventional manner.

[0100] The term "degree of polymerization" refers to an indicator that measures the size of polymer molecules.

[0101] All publications, patents, and published patent specifications cited in this article are incorporated herein in their entirety through citation.

[0102] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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.

[0103] Example 1:

[0104] Ingredient 1-1:

[0105] Raw materials 1-2:

[0106] In a 2000 mL round-bottom flask, 0.5 mol of raw material 1-1 and 0.5 mol of raw material 1-2 were dissolved in 600 mL of deionized water. 1% by weight of 4,4'-azobis(4-cyanopentanoic acid) of raw material 1-1 was added. The mixture was reacted at 100 °C for 6 hours until the reaction was complete, at which point intermediate product 1-1 was obtained.

[0107] Add 3% by mass of intermediate product 1-1 molybdenum trioxide, disperse evenly, heat to 80℃, slowly add 10% by mass of intermediate product 1-1 tert-butyl hydrogen peroxide, keep warm for 6 hours, reduce excess tert-butyl hydrogen peroxide with sodium sulfite aqueous solution, and after complete reaction, obtain target product I-1.

[0108] Yield: 89.46%

[0109] Molecular weight: 8743

[0110] Viscosity: 29 cps (100℃)

[0111] Example 2:

[0112] Raw material 2-1:

[0113] Raw material 2-2:

[0114] In a 2000 mL round-bottom flask, 0.5 mol of raw material 2-1 and 0.5 mol of raw material 2-2 were dissolved in 600 mL of water. 1% by weight of tert-butyl hydrogen peroxide of raw material 2-1 was added. The mixture was reacted at 120 °C for 8 hours. After the reaction was complete, intermediate product 2-1 was obtained.

[0115] Add 2% sodium tungstate of intermediate product 2-1 by mass, disperse evenly, heat to 80℃, slowly add 10% hydrogen peroxide of intermediate product 2-1 by mass, keep warm for 8 hours, reduce excess hydrogen peroxide with sodium sulfite aqueous solution, and after complete reaction, obtain target product I-2.

[0116] Yield: 91.25%

[0117] Molecular weight: 9275

[0118] Viscosity: 35 cps (100℃)

[0119] Example 3:

[0120] Ingredient 3-1:

[0121] Raw material 3-2:

[0122] Ingredient 3-3:

[0123] In a 5000 mL round-bottom flask, 0.5 mol of raw material 3-1, 0.5 mol of raw material 3-2, and 0.5 mol of raw material 3-3 were dissolved in 600 mL of water. 1.5% by weight of tert-butyl hydrogen peroxide of raw material 3-1 was added, and the reaction was continued at 120 °C for 8 hours. After the reaction was complete, intermediate product 3-1 was obtained.

[0124] Add 2% sodium tungstate of intermediate product 3-1 by mass, disperse evenly, heat to 70℃, slowly add 8% hydrogen peroxide of intermediate product 3-1 by mass, keep warm for 6 hours, reduce excess hydrogen peroxide with sodium sulfite aqueous solution, and after complete reaction, obtain target product I-3.

[0125] Yield: 88.73%

[0126] Molecular weight: 7140

[0127] Viscosity: 23 cps (100℃)

[0128] Example 4:

[0129] Raw material 4-1:

[0130] Raw material 4-2:

[0131] Raw material 4-3:

[0132] In a 5000 mL round-bottom flask, 1 mol of raw material 4-1, 0.5 mol of raw material 4-2, and 0.5 mol of raw material 4-3 were dissolved in 1000 mL of water. 1.5% by weight of tert-butyl hydrogen peroxide of raw material 4-1 was added. The mixture was reacted at 130 °C for 10 hours until the reaction was complete, and intermediate product 4-1 was obtained.

[0133] Add 2% (w / w) of intermediate product 4-1 phosphotungstic acid, disperse evenly, heat to 90℃, slowly add 8% (w / w) of intermediate product 4-1 hydrogen peroxide, keep warm for 7 hours, reduce excess hydrogen peroxide with sodium sulfite aqueous solution, and after complete reaction, obtain target product I-4.

[0134] Yield: 92.31%

[0135] Molecular weight: 10437

[0136] Viscosity: 45cps (100℃)

[0137] Comparative Example 1:

[0138] Polymer I-5, as shown in the following formula, was prepared according to the preparation methods of Manufacturing Examples 1 to 3 in patent document CN114551950A:

[0139]

[0140] Molecular weight: 6382

[0141] 1000 g of 2,2,6,6-tetramethyl-4-piperidinyl methacrylate, 14.6 g of 2,2'-azobis(2-methylpropionitrile) (AIBN), and 111.7 g of 4-cyano-4-(phenylthiocarbamoylthio)valerate were added to 2000 mL of anhydrous toluene to remove dissolved oxygen, followed by nitrogen purging. The reaction was carried out at approximately 60 °C for 5 hours, and polymerization was completed after cooling. The precipitate was collected, centrifuged to obtain the precipitate, and dried for 24 hours to obtain the intermediate.

[0142] 2 mol of the intermediate, sodium p-styrene sulfonate, and 14.6 g of AIBN were added to a solvent of water and methanol (solid content 50%). The reaction was carried out at 70°C for 5 hours, followed by cooling to complete the polymerization. The reactants were precipitated in hexane, centrifuged, and dried for 24 hours to obtain the copolymer.

[0143] 500g of the copolymer and 1720g of m-chloroperoxybenzoic acid were added to 5L of dichloromethane and stirred at 25°C for 12 hours to oxidize the copolymer. After the reactants precipitated in hexane, they were centrifuged and dried for 36 hours to obtain the target product.

[0144] Comparative Example 2:

[0145] Polymer I-6, as shown in Example 1 of patent document CN114824398B, was prepared according to the following formula:

[0146]

[0147] Molecular weight: 4800

[0148] First, add 6.02 mol of acrylic acid and 0.21 mol of α-ketoglutaric acid to a flask, then add 5000 mL of N,N-dimethylformamide (DMF). Stir at room temperature for 30 min until the solid is dispersed. Irradiate with ultraviolet light for 40 min. After the reaction is complete, dialyze for 5 days, and then freeze-dry to obtain polyacrylic acid.

[0149] Dissolve 15 mol of polyacrylic acid monomer in 20 L of water. Then add 30 mol of NH2-TEMPO and 30 mol of DMT-MM sequentially, and stir at 25 °C for 72 h. After the reaction is complete, add 4 L of 5 mol / L NaOH aqueous solution, stir for 30 min, and dialyze for 3 days to obtain PAA-grafted TEMPO polymer solution. Freeze-dry to obtain the target product.

[0150] Example 5: Electrochemical Performance Testing

[0151] This experiment tests electrochemical performance by assembling single-cell batteries, where the measured geometric area of ​​the battery is 2*2cm². 2 The battery separator uses a HoAMG-1204 anion exchange membrane, which is directly immersed in a 1 mol / L NaCl aqueous solution for 1 hour before use; the battery test mold is provided by Wuhan Chuxin Technology Co., Ltd.; the positive electrode electrolyte is 0.1 mol / L positive electrode active material + 1 mol / L NaCl aqueous solution; the negative electrode electrolyte is methyl viologen + 1 mol / L NaCl aqueous solution.

[0152] The assembled flow batteries were subjected to cycle stability tests at room temperature (25℃). The testing equipment was a Shenzhen Xinwei Battery Tester, with the test voltage set to 0.1-1.7V and the flow rate to 25mL / min.

[0153] in,

[0154] 1# is I-1 of a positive electrode material I for a polymeric flow battery (prepared from Example 1);

[0155] 2# is I-2 of a positive electrode material I for a polymeric flow battery (prepared from Example 2);

[0156] 3# is I-3 of a polymeric flow battery cathode material I (prepared from Example 3);

[0157] 4# is I-4 of a positive electrode material I for a polymeric flow battery (prepared from Example 4);

[0158] 5# is I-5 of a positive electrode material I for a polymeric flow battery (prepared from Comparative Example 1);

[0159] 6# is I-6 of a positive electrode material I for a polymeric flow battery (prepared from Comparative Example 2).

[0160] Its electrochemical properties are as follows:

[0161] Table 1: Comparison of Electrochemical Performance

[0162]

[0163]

[0164] 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, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0165] The foregoing embodiments and methods described in this invention may vary based on the capabilities, experience, and preferences of those skilled in the art.

[0166] The fact that the steps of the method are listed in a certain order in this invention does not constitute any restriction on the order of the method steps.

Claims

1. A TEMPO polymer, characterized in that, The TEMPO polymer comprises the structure shown in Formula I, and the structures shown in Formula II and / or Formula III: Among them, M1, M2, and M3 are cations, which are independently selected from: K + Na + NH4 + ; X is selected from: -O-, -NH-; R is selected from: -H, -L-(C1-C) 10 alkyl); L is selected from: single bond, C2-C 10 alkenyl, C2-C 10 Alkyne group, -(C0-C6 alkylene group)-(C3-C6 alkylene group) 10 Cycloalkylene)-, -(C0-C6 alkylene)-(C6-C 10 (arylene)-, -(C0-C6 alkylene)-(C3-C 10 -Hypercyclic groups: -O-, -S-, -C(O)-, -C(S)-, -C(O)O-, -C(O)N(R) A )-, -OC(O)-, -OC(O)O-, -OC(O)N(R A )-、-N(R A )-、-N(R A )C(O)-、-N(R A )C(O)O-、-N(R A )C(O)N(R B )-; R A R B Independently selected from: H, halogen, cyano, nitro, azide, C1-C 10 Alkyl, C2-C 10 alkenyl, C2-C 10 alkynyl, -(C0-C6 alkylene)-(C3-C 10 cycloalkyl), -(C0-C6 alkylene)-(C6-C 10 aryl), -(C0-C6 alkylene)-(3-10 membered heterocyclic), C1-C 10 Haloalkyl, -O(C) 0-10 alkyl), -CO(C) 0-10 Alkyl), -COO(C 0-10 Alkyl), -CON(C) 0-10 Alkyl)(C 0-10 Alkyl), -OCO(C 0-10 Alkyl), -OCOO(C 0-10 Alkyl), -OCON(C) 0-10 alkyl), -N(C) 0-10 Alkyl)(C 0-10 alkyl), -N(C) 0-10 Alkyl)CO(C 0-10 alkyl), -N(C) 0-10 Alkyl)COO(C 0-10 alkyl), -N(C) 0-10 Alkyl)CON(C 0-10 alkyl); n, m, and o are the aggregation degrees of the units, which are independent integers from 1 to 20.

2. The TEMPO polymer as claimed in claim 1, characterized in that, L is selected from: single bond, -(C0-C6 alkylene)-(C3-C6) 10 Cycloalkylene)-, -(C0-C6 alkylene)-(C6-C 10 (alpharyl)-; Preferably, L is selected from: single bond, More preferably, L is a single bond.

3. The TEMPO polymer as described in claim 1, characterized in that, R is selected from: H, Preferably, R is selected from: H, 4. The TEMPO polymer according to any one of claims 1-3, characterized in that, The TEMPO polymer comprises the structures shown in Formula I and Formula II; Preferably, the TEMPO polymer comprises the structures shown in Formula I and Formula III; Preferably, the TEMPO polymer comprises the structures shown in Formula I, Formula II and Formula III; Preferably, the molecular weight of the TEMPO polymer is 1000-50000; More preferably, the molecular weight of the TEMPO polymer is 8000-11000.

5. A method for preparing the TEMPO polymer as described in any one of claims 1-4, characterized in that, The preparation method includes dissolving compound A, compound B, and / or compound C in a solvent, adding an initiator to carry out a polymerization reaction to obtain an intermediate product, and adding an oxidant to carry out an oxidation reaction to obtain a TEMPO polymer. Compound A has the structure shown in Formula IV: The compound B has the structure shown in Formula V: The compound C has the structure shown in Formula VI:

6. The preparation method according to claim 5, characterized in that, Compound A has the following structure: Preferably, compound B has the following structure: More preferably, compound B has the following structure: Preferably, compound C has the following structure:

7. The preparation method according to claim 5, characterized in that, The solvent is water or an acidic solution; Preferably, the initiator is selected from: azo initiators and peroxide initiators; Preferably, the azo initiator is selected from: azobisisobutyramidine hydrochloride, 4,4'-azobis(4-cyanopentaic acid), azobisisobutyramidazole hydrochloride, azoisobutyramidazole cyanoformamide, dimethyl azobisisobutyrate, and azobisisopropylimidazoline hydrochloride. Preferably, the peroxide initiator is selected from: benzoyl peroxide, lauroyl peroxide, tert-butyl peroxypentanoate, tert-pentyl peroxypentanoate, tert-butyl peroxyacetate, tert-butyl peroxyneodecanate, tert-butyl peroxyisononanoate, tert-pentyl peroxybenzoate, tert-butyl peroxy-2-ethylhexyl carbonate, bis(4-tert-butylcyclohexyl) peroxydicarbonate, tert-butyl peroxy(2-ethylhexanoate), di(2-ethylhexyl) peroxydicarbonate, cumyl peroxyneodecanate, tert-butyl peroxymaleate, hydrogen peroxide, and tert-butyl hydroperoxide. More preferably, the initiator is 4,4'-azobis(4-cyanopentaic acid) or tert-butyl hydroperoxide; Preferably, the initiator has a mass of 0.1-5% of the mass of compound A, and more preferably 1-1.5%. Preferably, the molar ratio of compound A to compound B is 1:1-1.5, more preferably 1:1; Preferably, the molar ratio of compound A to compound C is 1:1-1.5, more preferably 1:1; Preferably, the polymerization reaction temperature is 0-150℃, more preferably 30-150℃, and even more preferably 100-130℃.

8. The preparation method according to claim 5, characterized in that, The oxidizing agent is selected from: benzoyl peroxide, lauroyl peroxide, tert-butyl peroxypentanoate, tert-pentyl peroxypentanoate, tert-butyl peroxyacetate, tert-butyl peroxyneodecanate, tert-butyl peroxyisononanoate, tert-pentyl peroxybenzoate, tert-butyl peroxy-2-ethylhexyl carbonate, bis(4-tert-butylcyclohexyl) peroxydicarbonate, tert-butyl peroxy(2-ethylhexanoate), di(2-ethylhexyl) peroxydicarbonate, cumyl peroxyneodecanate, tert-butyl maleate peroxide, hydrogen peroxide, and tert-butyl hydrogen peroxide. Preferably, the oxidant is hydrogen peroxide or tert-butyl hydrogen peroxide; Preferably, the mass of the oxidant is 5-20% of the mass of the intermediate product, and more preferably 8-10%. Preferably, a catalyst is also added to the oxidation reaction; Preferably, the catalyst is selected from: phosphomolybdic acid, phosphotungstic acid, sodium molybdate, sodium tungstate, silicomolybdic acid, silicostic acid, molybdenum trioxide, dextrose trioxide, and ethylenediaminetetraacetic acid; More preferably, the catalyst is molybdenum trioxide, sodium tungstate, or phosphotungstic acid; Preferably, the mass of the catalyst is 0.05-5% of the mass of the intermediate product; Preferably, the temperature of the oxidation reaction is 0-150℃, more preferably 30-150℃, and even more preferably 70-90℃.

9. The use of a TEMPO polymer as described in any one of claims 1-4 or a TEMPO polymer prepared by the preparation method described in any one of claims 5-8 as a positive electrode material in a polymeric flow battery.

10. A flow battery system, the flow battery system comprising a positive electrode reservoir, a negative electrode reservoir, and a flow battery stack; the two ends of the flow battery stack are respectively connected to the positive electrode reservoir and the negative electrode reservoir; the positive electrode reservoir contains a positive electrode material, the positive electrode material being the TEMPO polymer as described in any one of claims 1-4 or the TEMPO polymer prepared by the preparation method as described in any one of claims 5-8.

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