High-performance carbon felt electrode for zinc-bromine flow battery and preparation method of high-performance carbon felt electrode

Abstract

The invention belongs to the technical field of flow batteries, and particularly relates to a high-performance carbon felt electrode for a zinc-bromine flow battery and a preparation method of the high-performance carbon felt electrode. Comprising the following steps: respectively dissolving zinc salt and dimethylimidazole in methanol, carrying out stirring ultrasonic treatment to respectively obtain a solution A and a solution B, mixing the solution A and the solution B, and continuously stirring to obtain a solution C; washing and drying the original carbon felt, dipping the original carbon felt in the solution C, continuously stirring, washing and drying to obtain ZGF; the ZGF is carbonized in the argon atmosphere, and Z-ONGF is obtained; a three-electrode system is assembled by taking Z-ONGF as a working electrode, an original carbon felt as a counter electrode and a calomel saturation electrode as a reference electrode, electro-deposition is performed in an electroplating solution containing InCl34H2O and KBr, and the high-performance carbon felt electrode is obtained after cleaning and drying. According to the invention, the generation of zinc dendrites in the zinc-bromine flow battery can be effectively inhibited, and the electrochemical activity can be improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of liquid flow batteries, and particularly relates to a high-performance carbon felt electrode for a zinc-bromine flow battery and a preparation method thereof. BACKGROUND

[0002] Zinc-bromine flow batteries (ZBFBs) have shown great application prospects in the field of grid-scale energy storage due to their high theoretical energy density and low cost. However, traditional zinc-bromine flow batteries still face two key problems in actual operation: uneven zinc deposition and slow Br2 / Br - redox kinetics, resulting in short cycle life and limited power density of the battery.

[0003] During charging, zinc ions (Zn 2+ ) are reduced and deposited on the negative electrode surface to form metallic zinc. However, due to uneven electric field distribution on the electrode surface, zinc ions tend to preferentially deposit in areas with strong electric field (such as sharp tips or rough places), forming zinc dendrites. The growth of zinc dendrites not only pierces the separator, causing short circuit of the battery, but also reduces the coulombic efficiency and cycle stability of the battery. In addition, the kinetics of the Br2 / Br - redox reaction on the positive electrode side is slow, further limiting the power output and energy conversion efficiency of the battery.

[0004] Currently, to address the problem of zinc dendrites, methods such as optimizing electrolyte composition, introducing additives, or improving the separator are used to inhibit dendrite growth. The structure of the negative electrode can be optimized to limit the growth of zinc dendrites, while the reaction kinetics of zinc-bromine is enhanced to improve the electrochemical activity of the electrode. However, these methods often fail to balance the uniformity of zinc deposition and the improvement of reaction kinetics. Therefore, there is an urgent need to develop an electrode structure optimization strategy that can effectively regulate zinc deposition behavior, inhibit dendrite growth, and enhance Br2 / Br - reaction activity, to improve the cycle stability and electrochemical performance of zinc-bromine flow batteries. SUMMARY

[0005] To solve the problems in the prior art, the application provides a high-performance carbon felt electrode for a zinc-bromine flow battery and a preparation method thereof, which can effectively inhibit the generation of zinc dendrites in the zinc-bromine flow battery and improve the electrochemical activity.

[0006] To achieve the above-mentioned purposes, the application adopts the following technical solutions: In a first aspect, the application provides a preparation method of a high-performance carbon felt electrode for a zinc-bromine flow battery, comprising the following steps: The zinc salt and dimethyl imidazole are dissolved in methanol respectively, and then stirred and ultrasonically treated to obtain solution A and solution B respectively; solution A and solution B are mixed and continuously stirred to obtain solution C; After the original carbon felt is washed and dried, it is immersed in solution C and continuously stirred, and then washed and dried to obtain ZGF. The ZGF is carbonized under an argon atmosphere to obtain Z-ONGF. A three-electrode system is assembled with Z-ONGF as a working electrode, original carbon felt as a counter electrode and a saturated calomel electrode as a reference electrode, and then electrodeposited in an electroplating solution containing InCl3·4H2O and KBr, and washed and dried to obtain the high-performance carbon felt electrode.

[0007] Preferably, the zinc salt is zinc nitrate, zinc acetate, zinc sulfate or zinc chloride.

[0008] Preferably, the mass ratio of the zinc salt to dimethyl imidazole is 1: (1.2-1.6).

[0009] Preferably, the solid-liquid ratio of the zinc salt to methanol in solution A is 1g: (44-80)mL.

[0010] Preferably, the stirring and ultrasonic treatment is performed for 15-30min.

[0011] Preferably, the specific method for carbonizing the ZGF under an argon atmosphere is that the ZGF is carbonized at 600-1000℃ after being raised to 600-1000℃ at a temperature raising rate of 2-8℃ / min under an argon atmosphere for 1-5h.

[0012] Preferably, the original carbon felt is immersed in solution A and continuously stirred for 10-18h.

[0013] Preferably, the electroplating solution is prepared by dissolving InCl3·4H2O in a KBr solution, and then adding methane sulfonic acid as a hydrolysis inhibitor to obtain the electroplating solution; wherein the concentration of InCl3·4H2O in the electroplating solution is 5-10mmol / L, the concentration of KBr is 2-5mol / L, and the volume ratio of methane sulfonic acid is 9%-12%.

[0014] Preferably, the electrodeposition is performed under the conditions that the current density is 10-30mA / cm 2 , and the electrodeposition time is 5-10min.

[0015] In the second aspect, the application provides a high-performance carbon felt electrode for a zinc-bromine flow battery.

[0016] Compared with the prior art, the application has the following beneficial effects: The application constructs a porous structure with nitrogen and oxygen double-doped characteristics by in-situ growth of ZIF-8 on carbon felt and carbonization treatment. The structure not only significantly increases the specific surface area and surface hydrophilicity of the electrode, but also effectively enhances the adsorption capacity of nitrogen and oxygen functional groups to zinc atoms. At the same time, the porous structure improves the mass transfer performance of the electrode, realizes the uniform distribution and dense deposition of zinc ions, and effectively inhibits the formation of zinc dendrites. In addition, by depositing metal indium nanoparticles through electrodeposition, the catalytic activity of the electrode is further improved, and the reversible reaction kinetics of Br 2 / Br - electrode pairs is significantly promoted. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0018] Figure 1 Battery performance efficiency chart of the application examples 1-5; Figure 2 Battery performance comparison chart of the application example 3 and the comparative examples 1-2. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to understand the characteristics and effects of the application, the following will specifically explain and define the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific words used in the text are the usual meanings understood by those skilled in the art for the application, and in case of conflict, the definition in the specification shall prevail.

[0020] Theories or mechanisms described and disclosed herein, whether correct or wrong, should not limit the scope of the application in any way, i.e., the content of the application can be implemented without being limited by any specific theory or mechanism.

[0021] In this text, all features defined in the form of numerical range or percentage range, such as numerical value, quantity, content and concentration, are for the sake of brevity and convenience. Therefore, the description of numerical range or percentage range should be considered as having covered and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0022] In this document, "comprise", "comprising", "include", "including", "contain", "containing", "have", "having", or the like are open-ended terms, and do not exclude other elements or steps. For example, a process that "comprises" or "includes" a step does not exclude additional steps. Unless otherwise specified, "or" means "and / or". Unless otherwise specified, "comprising" can mean "consisting of" or "consisting essentially of".

[0023] In this document, all possible combinations of the various technical features described in the various embodiments or examples are not described. Therefore, as long as there is no contradiction in the combination of the technical features, the technical features in the various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered as the scope of the present specification.

[0024] The first object of the present application is to provide a preparation method of a high-performance carbon felt electrode for a zinc-bromine flow battery, comprising the following steps: Dissolve zinc salt and dimethylimidazole in methanol at a mass ratio of 1:(1.2-1.6) respectively, and stir and ultrasonically treat for 15-30 min to obtain solution A and solution B respectively. Stir continuously after mixing solution A and solution B to obtain solution C; wherein the solid-liquid ratio of zinc salt and methanol in solution A is 1 g:(44-80) mL.

[0025] After washing and drying the original carbon felt with ethanol and deionized water respectively, immerse in solution C and stir continuously for 10-18 h. After washing and drying, obtain ZGF. After carbonizing ZGF at a temperature rising rate of 2-8 ℃ / min to 600-1000 ℃ under an argon atmosphere for 1-5 h, obtain Z-ONGF. Assemble a three-electrode system with Z-ONGF as the working electrode, the original carbon felt as the counter electrode, and the saturated calomel electrode as the reference electrode, and electrodeposition in an electroplating solution containing InCl3·4H2O and KBr. After washing and drying, obtain the high-performance carbon felt electrode.

[0026] Assemble a three-electrode system with Z-ONGF electrode as the working electrode, the original carbon felt as the counter electrode, and the saturated calomel electrode as the reference electrode, and electrodeposition. Electrodeposition in an electroplating solution prepared by dissolving InCl3·4H2O in KBr, and adding methane sulfonic acid to inhibit hydrolysis. Electrodeposition at a current density of 10-30 mA / cm 2 After electrodeposition for 5-10 min, wash and dry the modified electrode with deionized water to obtain the final high-performance carbon felt electrode Z-ONGF-In.

[0027] The present application makes indium nanoparticles uniformly and densely distributed on the surface of carbon fibers by in-situ electrodeposition method, and the deposition of indium nanoparticles on carbon felt can change the surface electron distribution and reduce the active sites of hydrogen evolution reaction, thereby inhibiting the occurrence of hydrogen evolution side reaction. In addition, the strong interaction interface formed between the indium nanoparticles and the carbon fiber matrix ensures the efficiency and stability of electron transmission, so that the electrode can maintain excellent electrochemical reversibility in a wide current density range, as well as higher coulombic efficiency, voltage efficiency and energy efficiency, which provides a reliable guarantee for the long-term cycle stability of zinc-bromine flow battery.

[0028] The zinc salt is zinc nitrate, zinc acetate, zinc sulfate or zinc chloride. These zinc salts exhibit excellent solubility in methanol solvent and can be uniformly mixed with dimethyl imidazole at the molecular level, providing an ideal reaction environment for the controlled growth of ZIF-8 precursor. And it can be completely decomposed in the subsequent carbonization process, without introducing impurities, ensuring that the nitrogen and oxygen co-doped carbon skeleton obtained finally has a pure chemical composition and a uniform pore structure.

[0029] For example, the preparation method of the electroplating solution is: dissolving InCl3·4H2O in KBr solution, then adding methanesulfonic acid as a hydrolysis inhibitor to obtain the electroplating solution; wherein the concentration of InCl3·4H2O in the electroplating solution is 5-10 mmol / L, the concentration of KBr is 2-5 mol / L, and the volume ratio of methanesulfonic acid is 9%-12%. The stable coordination compound formed by KBr and indium ions in the electroplating solution effectively controls the electrochemical reduction process of indium, and the addition of methanesulfonic acid not only inhibits the hydrolysis tendency of indium ions, but also optimizes the conductivity of the electrolyte.

[0030] In the second aspect, the present application provides a high-performance carbon felt electrode for zinc-bromine flow battery. The original carbon felt is modified and then applied to zinc-bromine flow battery as an electrode. The modified carbon felt electrode not only retains the excellent conductivity and mechanical strength of the original carbon material, but also obtains enhanced zinc ion adsorption capacity and bromine-electrode pair catalytic activity through surface functionalization treatment. The unique microstructure design effectively solves the key problems of zinc dendrite growth and slow reaction kinetics in traditional zinc-bromine flow battery, significantly improves the cycle stability and energy conversion efficiency of the battery, and provides an ideal electrode material selection for the development of a new generation of high-performance flow battery.

[0031] The present application will be further described in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present application and not to limit the scope of the present application. In addition, it should be understood that those skilled in the art can make various modifications or changes to the present application after reading the content taught by the present application, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

[0032] The following examples use apparatus and equipment that are conventional in the art. The experimental methods in the following examples, unless otherwise specified, are generally conducted under conventional conditions, or under conditions recommended by the manufacturer. The following examples use various raw materials, unless otherwise specified, which are conventional commercially available products, and the specifications thereof are conventional in the art. In the specification of the present application and in the following examples, unless otherwise specified, "%" means weight percent, "parts" means weight parts, and the ratio means weight ratio.

[0033] Example 1 Step one: 0.5 g of zinc acetate and 0.6 g of dimethylimidazole were respectively dissolved in 22 mL of methanol, stirred and ultrasonically treated for 15 min, to obtain solution A and solution B respectively. After mixing solution A and solution B, continuous stirring was carried out to obtain solution C; Step two: the original carbon felt was washed with ethanol and deionized water respectively, and the dried carbon felt was immersed in solution C and continuously stirred for 10 h. After washing, the obtained carbon felt was dried to obtain ZGF. Step three: the synthesized ZGF was carbonized under an argon atmosphere at a temperature rising rate of 2 ℃ / min to 600 ℃ for 5 h to obtain Z-ONGF.

[0034] Step four: the obtained Z-ONGF electrode was used as a working electrode, the original carbon felt was used as a counter electrode, and a saturated calomel electrode was used as a reference electrode to assemble a three-electrode system for electrodeposition. InCl3·4H2O was dissolved in a KBr solution, and methanesulfonic acid was added as a hydrolysis inhibitor to obtain the plating solution; wherein the concentration of InCl3·4H2O in the plating solution was 5 mmol / L, the concentration of KBr was 2 mol / L, and the volume ratio of methanesulfonic acid was 9%. Electrodeposition was carried out at a constant current of 10 mA / cm 2 for 10 min, the modified electrode was washed with deionized water and dried to obtain the final high-performance carbon felt electrode Z-ONGF-In.

[0035] Example 2 Step one: 0.5 g of zinc acetate and 0.65 g of dimethylimidazole were respectively dissolved in 26 mL of methanol, stirred and ultrasonically treated for 20 min, to obtain solution A and solution B respectively. After mixing solution A and solution B, continuous stirring was carried out to obtain solution C; Step two: the original carbon felt was washed with ethanol and deionized water respectively, and the dried carbon felt was immersed in solution C and continuously stirred for 12 h. After washing, the obtained carbon felt was dried to obtain ZGF. Step three: the synthesized ZGF was carbonized under an argon atmosphere at a temperature rising rate of 4 ℃ / min to 700 ℃ for 4 h to obtain Z-ONGF.

[0036] Step four: the obtained Z-ONGF electrode is used as a working electrode, the original carbon felt is used as a counter electrode, and a saturated calomel electrode is used as a reference electrode to assemble a three-electrode system for electrodeposition. InCl3·4H2O is dissolved in a KBr solution, and methanesulfonic acid is added as a hydrolysis inhibitor to obtain the plating solution; wherein the concentration of InCl3·4H2O in the plating solution is 6 mmol / L, the concentration of KBr is 3 mol / L, and the volume percentage of methanesulfonic acid is 9.6%. Electrodeposition is performed at a constant current of 15 mA / cm 2 for 8 min, the modified electrode is washed with deionized water and dried to obtain the final high-performance carbon felt electrode Z-ONGF-In.

[0037] Example 3 Step one: 0.5 g of zinc acetate and 0.7 g of dimethylimidazole are respectively dissolved in 30 mL of methanol, stirred and ultrasonically treated for 25 min to obtain solution A and solution B respectively. After mixing solution A and solution B, continuous stirring is performed to obtain solution C; Step two: the original carbon felt is washed with ethanol and deionized water respectively, and the dried carbon felt is immersed in solution C and continuously stirred for 14 h. After washing, the obtained carbon felt is dried to obtain ZGF. Step three: the synthesized ZGF is carbonized at 800℃ at a heating rate of 6℃ / min for 3 h under an argon atmosphere to obtain Z-ONGF.

[0038] Step four: the obtained Z-ONGF electrode is used as a working electrode, the original carbon felt is used as a counter electrode, and a saturated calomel electrode is used as a reference electrode to assemble a three-electrode system for electrodeposition. InCl3·4H2O is dissolved in a KBr solution, and methanesulfonic acid is added as a hydrolysis inhibitor to obtain the plating solution; wherein the concentration of InCl3·4H2O in the plating solution is 7 mmol / L, the concentration of KBr is 4 mol / L, and the volume percentage of methanesulfonic acid is 10.4%. Electrodeposition is performed at a constant current of 20 mA / cm 2 for 7 min, the modified electrode is washed with deionized water and dried to obtain the final high-performance carbon felt electrode Z-ONGF-In.

[0039] Example 4 Step one: 0.5 g of zinc acetate and 0.75 g of dimethylimidazole are respectively dissolved in 35 mL of methanol, stirred and ultrasonically treated for 30 min to obtain solution A and solution B respectively. After mixing solution A and solution B, continuous stirring is performed to obtain solution C; Step two: the original carbon felt is washed with ethanol and deionized water respectively, and the dried carbon felt is immersed in solution C and continuously stirred for 16 h. After washing, the obtained carbon felt is dried to obtain ZGF. Step three: the synthesized ZGF was carbonized for 2h under an argon atmosphere after being raised to 900℃ at a temperature raising rate of 7℃ / min, to obtain Z-ONGF.

[0040] Step four: the obtained Z-ONGF electrode was used as a working electrode, the original carbon felt was used as a counter electrode, and a saturated calomel electrode was used as a reference electrode to assemble a three-electrode system for electrodeposition. InCl3·4H2O was dissolved in a KBr solution, and methanesulfonic acid was added as a hydrolysis inhibitor to obtain the electroplating solution; wherein the concentration of InCl3·4H2O in the electroplating solution was 8mmol / L, the concentration of KBr was 4.5mol / L, and the volume percentage of methanesulfonic acid was 11.4%. Electrodeposition was performed at a constant current of 25mA / cm 2 for 6min, the modified electrode was washed with deionized water and dried to obtain the final high-performance carbon felt electrode Z-ONGF-In.

[0041] Example 5 Step one: 0.5g of zinc acetate and 0.8g of dimethylimidazole were respectively dissolved in 40mL of methanol, stirred and ultrasonically treated for 30min to obtain solution A and solution B respectively, and the mixed solution A and solution B were continuously stirred to obtain solution C; Step two: the original carbon felt was washed with ethanol and deionized water respectively, and the dried carbon felt was immersed in solution C and continuously stirred for 18h, and the obtained carbon felt was washed and dried to obtain ZGF. Step three: the synthesized ZGF was carbonized for 1h under an argon atmosphere after being raised to 1000℃ at a temperature raising rate of 8℃ / min, to obtain Z-ONGF.

[0042] Step four: the obtained Z-ONGF electrode was used as a working electrode, the original carbon felt was used as a counter electrode, and a saturated calomel electrode was used as a reference electrode to assemble a three-electrode system for electrodeposition. InCl3·4H2O was dissolved in a KBr solution, and methanesulfonic acid was added as a hydrolysis inhibitor to obtain the electroplating solution; wherein the concentration of InCl3·4H2O in the electroplating solution was 10mmol / L, the concentration of KBr was 5mol / L, and the volume percentage of methanesulfonic acid was 12%. Electrodeposition was performed at a constant current of 30mA / cm 2 for 5min, the modified electrode was washed with deionized water and dried to obtain the final high-performance carbon felt electrode Z-ONGF-In.

[0043] Example 6 Step one: 0.5g of zinc nitrate and 0.8g of dimethylimidazole were respectively dissolved in 40mL of methanol, stirred and ultrasonically treated for 30min to obtain solution A and solution B respectively, and the mixed solution A and solution B were continuously stirred to obtain solution C; Step two: the original carbon felt was cleaned with ethanol and deionized water respectively, and the dried carbon felt was immersed in solution C and continuously stirred for 18 h. The obtained carbon felt was cleaned and dried to obtain ZGF. Step three: the synthesized ZGF was carbonized at 1000℃ under an argon atmosphere at a heating rate of 8℃ / min for 1h to obtain Z-ONGF.

[0044] Step four: the obtained Z-ONGF electrode was used as the working electrode, the original carbon felt was used as the counter electrode, and the saturated calomel electrode was used as the reference electrode to assemble a three-electrode system for electrodeposition. InCl3·4H2O was dissolved in a KBr solution, and methanesulfonic acid was added as a hydrolysis inhibitor to obtain the plating solution; wherein the concentration of InCl3·4H2O in the plating solution was 10 mmol / L, the concentration of KBr was 5 mol / L, and the volume ratio of methanesulfonic acid was 12%. Electrodeposition was carried out at a constant current of 30 mA / cm 2 for 5 min, and the modified electrode was cleaned with deionized water and dried to obtain the final high-performance carbon felt electrode Z-ONGF-In.

[0045] Example 7 Step one: 0.5 g of zinc sulfate and 0.8 g of dimethylimidazole were respectively dissolved in 40 mL of methanol, stirred and ultrasonically treated for 30 min to obtain solution A and solution B respectively. The mixed solution A and solution B were continuously stirred to obtain solution C; Step two: the original carbon felt was cleaned with ethanol and deionized water respectively, and the dried carbon felt was immersed in solution C and continuously stirred for 18 h. The obtained carbon felt was cleaned and dried to obtain ZGF. Step three: the synthesized ZGF was carbonized at 1000℃ under an argon atmosphere at a heating rate of 8℃ / min for 1h to obtain Z-ONGF.

[0046] Step four: the obtained Z-ONGF electrode was used as the working electrode, the original carbon felt was used as the counter electrode, and the saturated calomel electrode was used as the reference electrode to assemble a three-electrode system for electrodeposition. InCl3·4H2O was dissolved in a KBr solution, and methanesulfonic acid was added as a hydrolysis inhibitor to obtain the plating solution; wherein the concentration of InCl3·4H2O in the plating solution was 10 mmol / L, the concentration of KBr was 5 mol / L, and the volume ratio of methanesulfonic acid was 12%. Electrodeposition was carried out at a constant current of 30 mA / cm 2 for 5 min, and the modified electrode was cleaned with deionized water and dried to obtain the final high-performance carbon felt electrode Z-ONGF-In.

[0047] Example 8 Step one: 0.5g zinc chloride and 0.8g dimethylimidazole were dissolved in 40mL methanol respectively, stirred and ultrasonically treated for 30min, to obtain solution A and solution B respectively, then solution A and solution B were mixed and continuously stirred to obtain solution C; Step two: the original carbon felt was washed with ethanol and deionized water respectively, and then the dried carbon felt was immersed in solution C and continuously stirred for 18h, then the obtained carbon felt was washed and dried to obtain ZGF. Step three: the synthesized ZGF was carbonized under argon atmosphere at a heating rate of 8℃ / min to 1000℃ for 1h to obtain Z-ONGF.

[0048] Step four: the obtained Z-ONGF electrode was used as the working electrode, the original carbon felt was used as the counter electrode, and the saturated calomel electrode was used as the reference electrode to assemble a three-electrode system for electrodeposition. InCl3·4H2O was dissolved in KBr solution, and then methane sulfonic acid was added as a hydrolysis inhibitor to obtain the plating solution; wherein the concentration of InCl3·4H2O in the plating solution was 10mmol / L, the concentration of KBr was 5mol / L, and the volume ratio of methane sulfonic acid was 12%. The electrodeposition was carried out at a constant current of 30mA / cm 2 for 5min, the modified electrode was washed with deionized water and dried to obtain the final high-performance carbon felt electrode Z-ONGF-In.

[0049] Comparative example 1 Step one: 0.5g zinc acetate and 0.7g dimethylimidazole were dissolved in 30mL methanol respectively, stirred and ultrasonically treated for 25min to obtain solution A and solution B respectively, then solution A and solution B were mixed and continuously stirred to obtain solution C. Step two: the original carbon felt was washed with ethanol and deionized water respectively, and then the dried carbon felt was immersed in solution C and continuously stirred for 14h, then the obtained carbon felt was washed and dried to obtain ZGF. Step three: the synthesized ZGF was carbonized under argon atmosphere at a heating rate of 6℃ / min to 800℃ for 3h to obtain the modified carbon felt Z-ONGF.

[0050] Comparative example 2 Step one: the original carbon felt was used as the working electrode and the counter electrode, and the saturated calomel electrode was used as the reference electrode to assemble a three-electrode system for electrodeposition. InCl3·4H2O was dissolved in KBr solution, and then methane sulfonic acid was added as a hydrolysis inhibitor to obtain the plating solution; wherein the concentration of InCl3·4H2O in the plating solution was 7mmol / L, the concentration of KBr was 4mol / L, and the volume ratio of methane sulfonic acid was 10.4%. The electrodeposition was carried out at a constant current of 20mA / cm 2 for 7min.

[0051] Step 2: The modified electrode is washed with deionized water and dried to obtain the final modified carbon felt electrode GF-In.

[0052] like Figure 1 As shown in FIG, the battery performance efficiency of the electrodes of Examples 1 to 5 is stably maintained at more than 80% during the cycle number from 0 to 100, indicating that the electrodes of the present invention have a good effect on improving the battery performance efficiency; Figure 2 As shown, both the in-situ growth method and the in-situ electrodeposition method have shown positive and effective effects. Throughout the entire process of cycle number from 10 to 100, the battery efficiency of the electrode application in Example 3 is always maintained at a high level, basically close to or even reaching an efficient value of about 90% at some cycle points. Although Comparative Examples 1 and 2 also show certain performance improvements and the battery efficiency can be maintained at around 80%, there is still a certain gap compared to Example 3, indicating that the effect of composite modification is better and can more comprehensively improve the overall performance of the battery.

[0053] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing a high-performance carbon felt electrode for zinc-bromine flow battery, characterized in that: The following steps are involved: Dissolve zinc salt and dimethylimidazole in methanol, stir and ultrasonicate to obtain solution A and solution B, respectively. Mix solution A and solution B and continue stirring to obtain solution C. The original carbon felt was washed and dried, immersed in solution C with continuous stirring, and then washed and dried to obtain ZGF; ZGF was carbonized under argon atmosphere to obtain Z-ONGF; A three-electrode system was assembled with Z-ONGF as the working electrode, the original carbon felt as the counter electrode, and the calomel saturated electrode as the reference electrode. The system was electrodeposited in an electroplating solution containing InCl3•4H2O and KBr, and the high-performance carbon felt electrode was obtained after cleaning and drying.

2. The method for preparing a high-performance carbon felt electrode for zinc-bromine flow battery according to claim 1, characterized in that: The zinc salt is zinc nitrate, zinc acetate, zinc sulfate or zinc chloride.

3. The method for preparing a high-performance carbon felt electrode for zinc-bromine flow battery according to claim 1, characterized in that: The mass ratio of the zinc salt to dimethylimidazole is 1:(1.2-1.6).

4. The method for preparing a high-performance carbon felt electrode for zinc-bromine flow battery according to claim 1, characterized in that: The solid-to-liquid ratio of zinc salt to methanol in the solution A is 1 g: (44-80) mL.

5. The method for preparing a high-performance carbon felt electrode for zinc-bromine flow battery according to claim 1, characterized in that: The stirring and ultrasonic treatment time is 15 to 30 minutes.

6. The method for preparing a high-performance carbon felt electrode for zinc-bromine flow battery according to claim 1, characterized in that: The specific method of carbonizing ZGF under an argon atmosphere is: heating ZGF to 600° C. to 1000° C. at a heating rate of 2° C. / min under an argon atmosphere and then carbonizing for 1 to 5 hours.

7. The method for preparing a high-performance carbon felt electrode for zinc-bromine flow battery according to claim 1, characterized in that: The original carbon felt is immersed in solution A and stirred continuously for 10 to 18 hours.

8. The method for preparing a high-performance carbon felt electrode for zinc-bromine flow battery according to claim 1, characterized in that: The preparation method of the electroplating solution is: dissolving InCl3•4H2O in a KBr solution, and then adding methanesulfonic acid as a hydrolysis inhibitor to obtain the electroplating solution; wherein the concentration of InCl3•4H2O in the electroplating solution is 5~10mmol / L, the concentration of KBr is 2~5mol / L, and the volume proportion of methanesulfonic acid is 9%~12%.

9. The method for preparing a high-performance carbon felt electrode for zinc-bromine flow battery according to claim 1, characterized in that: The electrodeposition conditions are: at a current density of 10-30 mA / cm 2 Electrodeposition for 5 to 10 minutes.

10. A high performance carbon felt electrode for zinc-bromine flow battery, characterized in that: The method is prepared according to any one of claims 1 to 9.

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