Carbon material flow battery electrode material and preparation method and application thereof

Abstract

The invention provides a carbon material flow battery electrode material as well as a preparation method and application thereof, and relates to the technical field of battery electrodes. A carbon material is used as a basic raw material, and laser surface dot matrix modification is performed on the carbon material after pretreatment processes such as ultrasonic cleaning, acid treatment, drying, roasting and the like, so that the flow battery electrode material is obtained. According to the preparation method disclosed by the invention, on the premise of ensuring good mechanical properties of the carbon material, the electrode activity, the single battery performance and the hydrophilic infiltration performance of the carbon material are remarkably improved, the reaction active sites of the carbon material are increased, and the accessibility and the reaction activity of an electrolyte are improved, so that the comprehensive performance of a flow battery prepared by taking the carbon material as the electrode material is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery electrodes, and in particular to a carbon material liquid flow battery electrode material and a preparation method and application thereof. Background Art

[0002] With the rapid development of science and technology and industry, energy consumption is increasing. Traditional fossil energy is facing depletion, and traditional fossil energy will release greenhouse gases and elements such as sulfur and nitrogen during use, causing many environmental problems such as greenhouse effect and air pollution. Therefore, new energy is an inevitable trend of development. However, affected by the characteristics of natural resources, new energy has unstable, discontinuous, and non-steady-state characteristics that are easily affected by external factors, and cannot be directly incorporated into the power grid for use. Therefore, it is necessary to maintain the stability of the power grid system through the frequency modulation effect of energy storage equipment to reduce peak loads and fill valleys.

[0003] Among electrochemical energy storage materials, lithium battery energy storage can only achieve short-term energy storage, and is greatly affected by external temperature, and there is a greater risk of explosion. Liquid flow batteries have a longer energy storage time (> 4h), long service life, good stability, are generally water-based, have a lower risk of explosion, and are simple to handle afterwards. They are considered to be the most promising green energy storage material.

[0004] In liquid flow batteries, battery electrodes are generally made of carbon materials, which can provide channels for the flow of electrolytes and do not directly participate in the reaction. They provide reaction sites for electrochemically active substances to ensure that the electrodes transfer electrons and convert ions on their surfaces. Therefore, electrode materials are required to have high activity and good corrosion resistance, hydrophilic wettability, high conductivity and mechanical properties to meet the use requirements of liquid flow batteries.

[0005] The Chinese patent with publication number CN 116742030 A provides an electrode for a liquid flow battery and a liquid flow battery, which increases the contact area between the electrolyte and the electrode by stacking multiple layers of porous carbon paper. However, this method increases the contact resistance and the mechanical properties of the carbon paper are poor, which is prone to deformation and rupture, resulting in the risk of leakage.

[0006] The Chinese patent application with publication number CN 102136579 A provides a modification method for graphite felt for all-vanadium liquid flow battery electrodes. The method first oxidizes the graphite felt with air, then modifies it with hydrogen peroxide solution or Fenton reagent, and finally opens multiple grooves on its surface. The modified graphite felt has an increased number of oxygen-containing groups, which can significantly improve hydrophilicity and increase the reaction area of ​​the electrode itself. However, if the method opens too many holes or the spacing is large, the mechanical properties of the material will be greatly reduced, and it will be easy to be pulled and broken during the assembly and compression process, resulting in serious deformation.

[0007] It can be seen that although there are currently many ways to modify carbon electrode materials to increase their contact area and reaction area, these methods all cause the loss of mechanical properties of the materials to varying degrees, thereby affecting the overall performance of the flow battery. Therefore, how to improve the active sites of the electrode materials without affecting their mechanical properties is of great significance to the development of flow batteries. Summary of the invention

[0008] To solve the above problems, the present invention provides a method for preparing a carbon material flow battery electrode material and its application. The present invention uses laser energy to modify the surface of the carbon material, which can increase its reactive sites and improve the accessibility and reactive activity of the electrolyte without destroying the main structure of the carbon material and maintaining the original mechanical strength of the carbon material.

[0009] The method for preparing the carbon material flow battery electrode of the present invention comprises the following steps:

[0010] S1. Add the carbon material into anhydrous ethanol and perform ultrasonic cleaning. After cleaning, dry the carbon material to remove impurities such as oil on the surface of the carbon material;

[0011] S2, soaking the dried carbon material in an acid solution for acid treatment, and after the treatment, washing with ultrapure water until the pH value of the washing solution is 5-7;

[0012] S3, drying and roasting the acid-treated carbon material, and cooling it naturally after roasting for later use;

[0013] S4. Performing laser surface lattice modification on the carbon material to obtain a carbon material flow battery electrode material.

[0014] Further, the carbon material is graphite felt, carbon felt, carbon paper or carbon cloth. Preferably, the carbon material is graphite felt, carbon paper or carbon cloth.

[0015] Furthermore, the carbon material has a thickness of 0.2 to 5 mm.

[0016] Furthermore, the ultrasonic cleaning time in S1 is 0.2 to 1 h, and the ultrasonic power is 400 to 450 W. Preferably, the ultrasonic cleaning time in S1 is 0.5 h, and the ultrasonic power is 420 W.

[0017] Furthermore, in said S1, the drying temperature is 40°C to 80°C, and the drying time is 0.2 to 1 hour. Preferably, in said S1, the drying temperature is 60°C, and the drying time is 0.5 hour.

[0018] Furthermore, the acidic solution in S2 is a sulfuric acid solution.

[0019] Furthermore, the concentration of the acidic solution in S2 is 0.5M.

[0020] Further, the acid treatment temperature in S2 is 60°C to 100°C, and the acid treatment time is 0.5 to 5 hours. Preferably, the acid treatment temperature in S2 is 80°C, and the acid treatment time is 1.5 hours.

[0021] Furthermore, the drying temperature in S3 is 50°C to 100°C, and the drying time is 0.5 to 1 hour. Preferably, the drying temperature in S3 is 80°C, and the drying time is 0.5 hour.

[0022] Furthermore, the calcination temperature in S3 is 300°C to 500°C, the calcination time is 1 to 5 hours, and the calcination is carried out in an air atmosphere. Preferably, the calcination temperature in S3 is 450°C, and the calcination time is 1 hour.

[0023] Furthermore, the laser energy of the laser surface lattice modification is 10 to 50 W. Preferably, the laser energy of the laser surface lattice modification is 30 W.

[0024] Furthermore, the diameter of the lattice holes of the laser surface lattice modification is 0.3 to 5 mm. Preferably, the diameter of the lattice holes of the laser surface lattice modification is 0.3 to 2 mm.

[0025] The present invention also provides a carbon material liquid flow battery electrode material prepared according to the above method.

[0026] The invention discloses an application of the carbon material liquid flow battery electrode material in the preparation of liquid flow batteries.

[0027] Compared with the prior art, the beneficial technical effects of the present invention are:

[0028] The present invention significantly increases the surface activity of the carbon material and improves the electrochemical performance of the electrode without affecting the mechanical properties of the carbon material through appropriate pretreatment technology and laser surface lattice modification.

[0029] The preparation method provided by the invention has clear steps, simple process, easy operation and is suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below in conjunction with the accompanying drawings.

[0031] Figure 1 This is a graph showing the contact angle test results of the graphite felt flow battery electrode material in Example 1;

[0032] Figure 2 This is a graph showing the contact angle test results of the graphite felt flow battery electrode material in Example 2;

[0033] Figure 3This is a graph showing the contact angle test results of the graphite felt flow battery electrode material in Example 3;

[0034] Figure 4 This is the contact angle test result diagram of untreated graphite felt raw material;

[0035] Figure 5 The surface microstructure and 3D surface profile schematic diagram of the graphite felt flow battery electrode material in Example 1;

[0036] Figure 6 Schematic diagram of the surface microstructure and 3D surface profile of the graphite felt flow battery electrode material of Example 2;

[0037] Figure 7 Schematic diagram of the surface microstructure and 3D surface profile of the graphite felt flow battery electrode material of Example 3;

[0038] Figure 8 Schematic diagram of the surface microstructure and 3D surface profile of untreated graphite felt raw material;

[0039] Fig. 9 The performance test results of the flow battery composed of Examples 1-3 and untreated graphite felt;

[0040] Fig.10 This is a graph showing the contact angle test results of the carbon paper flow battery electrode material in Example 5;

[0041] Fig.11 This is a graph showing the contact angle test results of the carbon paper flow battery electrode material in Example 6;

[0042] Fig.12 This is a graph showing the contact angle test results of the carbon paper flow battery electrode material in Example 7;

[0043] Fig.13 This is the contact angle test result of untreated carbon paper raw material;

[0044] Fig.14 Schematic diagram of the surface microstructure and 3D surface profile of the carbon paper flow battery electrode material in Example 5;

[0045] Fig.15 Schematic diagram of the surface microstructure and 3D surface profile of the carbon paper flow battery electrode material in Example 6;

[0046] Fig.16 Schematic diagram of the surface microstructure and 3D surface profile of the carbon paper flow battery electrode material of Example 7;

[0047] Fig.17 Schematic diagram of the surface microstructure and 3D surface profile of untreated carbon paper raw materials;

[0048] Fig.18 This is a graph showing the contact angle test results of the carbon cloth flow battery electrode material in Example 8;

[0049] Fig.19 This is a graph showing the contact angle test results of the carbon cloth flow battery electrode material in Example 9;

[0050] Fig. 20 This is a graph showing the contact angle test results of the carbon cloth liquid flow battery electrode material in Example 10;

[0051] Fig.21 This is the contact angle test result of untreated carbon cloth raw material;

[0052] Fig. 22 Schematic diagram of the surface microstructure and 3D surface profile of the carbon cloth liquid flow battery electrode material of Example 8;

[0053] Fig.23 Schematic diagram of the surface microstructure and 3D surface profile of the carbon cloth flow battery electrode material of Example 9;

[0054] Fig.24 Schematic diagram of the surface microstructure and 3D surface profile of the carbon cloth liquid flow battery electrode material of Example 10;

[0055] Fig.25 Schematic diagram of the surface microstructure and 3D surface profile of untreated carbon cloth raw material. DETAILED DESCRIPTION

[0056] The present invention provides a method for preparing a carbon material flow battery electrode, comprising the following steps:

[0057] S1. Add the carbon material into anhydrous ethanol and perform ultrasonic cleaning. After cleaning, dry the carbon material to remove impurities such as oil on the surface of the carbon material;

[0058] S2, soaking the dried carbon material in an acid solution for acid treatment, and after the treatment, washing with ultrapure water until the pH value of the washing solution is 5-7;

[0059] S3, drying and roasting the acid-treated carbon material, and cooling it naturally after roasting for later use;

[0060] S4. Performing laser surface lattice modification on the carbon material to obtain a carbon material flow battery electrode material.

[0061] In one embodiment, the carbon material is graphite felt, carbon felt, carbon paper or carbon cloth.

[0062] In one embodiment, the carbon material is graphite felt, carbon paper or carbon cloth.

[0063] In one embodiment, the carbon material has a thickness of 0.2 to 5 mm.

[0064] The present invention strictly limits the thickness of the carbon material. Appropriate thickness can ensure that the electrode has good conductivity and electrochemical activity, while providing sufficient mechanical strength to ensure that the structure remains stable during battery operation and avoid damage caused by mechanical stress. In addition, the thickness of the electrode affects its specific surface area and mass transfer efficiency. Appropriate thickness can provide sufficient reaction area while ensuring that the electrolyte can effectively penetrate and flow, thereby improving the overall performance of the battery. Finally, limiting the thickness can optimize the utilization rate of the material, reduce waste, and thus reduce costs. The above is the effect of thickness on the conventional performance of the battery. In addition, more importantly, the thickness of the carbon material has an important influence on achieving a good laser surface lattice modification effect. Thicker carbon materials will cause increased conduction and accumulation of heat inside the material, thereby affecting the depth and uniformity of laser ablation, while thinner materials are more likely to achieve uniform heat distribution, which helps to obtain a consistent surface modification effect. In addition, the material thickness also affects the surface morphology after laser ablation. Thicker materials may form deeper ablation pits and cracks, while thinner materials are more likely to form a uniform surface structure. Material thickness also affects the absorption efficiency of laser energy. Thinner materials can absorb laser energy more effectively, thereby improving ablation efficiency and surface modification effects. Finally, appropriate thickness can ensure that the material maintains mechanical strength and stability during laser processing and avoid deformation or damage caused by being too thin. It can be seen that only within an appropriate range can carbon materials achieve good lattice modification effects without damaging material properties. Too thin or too thick will result in poor modification, resulting in unqualified products.

[0065] In one embodiment, the ultrasonic cleaning time in S1 is 0.2 to 1 h, and the ultrasonic power is 420 W.

[0066] In one embodiment, the ultrasonic cleaning time in S1 is 0.5 h.

[0067] In one embodiment, the drying temperature in S1 is 40° C. to 80° C., and the drying time is 0.2 to 1 h.

[0068] In one embodiment, the drying temperature in S1 is 60° C. and the drying time is 0.5 h.

[0069] In one embodiment, the acidic solution in S2 is a sulfuric acid solution.

[0070] In one embodiment, the concentration of the acidic solution in S2 is 0.5M.

[0071] In one embodiment, the acid treatment temperature in S2 is 60°C to 100°C, and the acid treatment time is 0.5 to 5 hours. In one embodiment, the acid treatment temperature in S2 is 80°C, and the acid treatment time is 1.5 hours.

[0072] In one embodiment, the drying temperature in S3 is 50° C. to 100° C., and the drying time is 0.5 to 1 hour.

[0073] In one embodiment, the drying temperature in S3 is 80° C. and the drying time is 0.5 h.

[0074] In one embodiment, the calcination temperature in S3 is 300° C. to 500° C., the calcination time is 1 to 5 hours, and the calcination is performed in an air atmosphere.

[0075] In one embodiment, the calcination temperature in S3 is 450° C. and the calcination time is 1 hour.

[0076] The present invention removes residual moisture and organic impurities in the carbon material through a process of baking after drying, and at the same time makes the structure of the material more stable through high temperature treatment, increases activation sites, and enhances the conductivity and electrochemical properties of the material. Appropriate drying temperature and time can effectively remove moisture in the material, and prevent the material structure from being damaged due to water evaporation during the baking process. The high temperature treatment during the baking process can change the microstructure and surface morphology of the carbon material, making the surface of the material more uniform and flat, which is conducive to the uniformity and consistency of laser modification. In addition, baking can remove organic impurities and residual moisture in the material, enhance the conductivity and chemical stability of the material, and thus improve the effect of laser modification. The baked material usually has better thermal conductivity, which helps to distribute heat more evenly during the laser modification process, avoiding local overheating or uneven ablation. Finally, the appropriate baking temperature and time can improve the mechanical strength and stability of the material, and ensure that the material will not be deformed or damaged due to thermal stress during the laser treatment process. Therefore, the present invention strictly limits the baking temperature and baking time of the carbon material to provide a good modification basis for subsequent laser surface lattice treatment.

[0077] In one embodiment, the laser energy of the laser surface lattice modification is 10-50W.

[0078] In one embodiment, the laser energy of the laser surface lattice modification is 30W.

[0079] In one embodiment, the diameter of the lattice holes of the laser surface lattice modification is 0.3-5 mm.

[0080] In one embodiment, the diameter of the lattice holes of the laser surface lattice modification is 0.3-2 mm.

[0081] The present invention ensures the uniformity of the modification effect and the integrity of the material by limiting the laser energy and the diameter of the lattice holes of the laser surface lattice modification.

[0082] Appropriate laser energy can control the depth and range of thermal damage, avoid excessive ablation and material damage caused by excessive energy, and optimize the uniformity and fineness of surface ablation, form a uniform lattice structure, and improve the electrochemical properties of the material. In addition, limiting the laser energy can prevent the material from being affected by thermal stress and deformation, affecting its mechanical strength and stability, and improve processing efficiency, reduce unnecessary energy consumption, and thus reduce costs.

[0083] The appropriate lattice hole diameter can ensure uniform distribution of laser energy, avoid local overheating or excessive ablation, and thus obtain a uniform surface modification effect. In addition, the lattice hole diameter affects the surface morphology after laser ablation. The appropriate aperture can form a uniform lattice structure, which helps to improve the electrochemical properties of the material without damaging the mechanical strength of the material itself. Limiting the lattice hole diameter can also prevent the material from being deformed or damaged due to thermal stress during laser processing, ensuring the mechanical strength and stability of the material. Finally, the appropriate lattice hole diameter can improve processing efficiency, reduce unnecessary energy consumption, and thus reduce costs.

[0084] In general, the present invention limits the type and thickness of the material itself, limits the parameters of the pre-treatment processes such as drying and roasting, and limits the laser energy and lattice hole diameter of the laser surface lattice modification to ensure that the modified material has good mechanical properties, and the electrode activity, single cell performance, and hydrophilic wettability are greatly improved. Therefore, the above parameters complement each other and restrict each other, and need to be selected and limited within the scope defined by the present invention according to the changes in the type of carbon material and the needs of actual production.

[0085] The present invention also provides a carbon material liquid flow battery electrode material prepared according to the above method.

[0086] The invention discloses an application of the carbon material liquid flow battery electrode material in preparing liquid flow battery electrodes.

[0087] The technical solution provided by the present invention is further described below in conjunction with embodiments.

[0088] The graphite felt used in the specific implementation manner of the present invention is provided by Wuhan Chuxin Technology Co., Ltd., the carbon paper model is GDB-24, purchased from Shenzhen General Hydrogen Energy Technology Co., Ltd., and the carbon cloth model is 122PLG-XX4542, purchased from Jiaxing Naco New Materials Co., Ltd.; the laser surface dot matrix modification is carried out using a laser etching engraving and cutting system; the single cell fixture used in the product performance test is purchased from Wuhan Chuxin Technology Co., Ltd., and the fixture specification is 5cm×5cm.

[0089] Example 1 A method for preparing a graphite felt flow battery electrode material, the steps are as follows:

[0090] Take a graphite felt with a thickness of 4.35mm and a specification of 5cm×5cm, and use anhydrous ethanol to ultrasonically clean it at 420W for 0.5h. Place the cleaned graphite felt in a 60℃ oven for 0.5h, and then soak it in a 0.5M sulfuric acid solution at 80℃ for 1.5h. Take out the graphite felt and rinse it with ultrapure water until the pH value of the washing liquid is 6.5. Then place the graphite felt in an 80℃ oven for 0.5h, take it out and place it in a muffle furnace with an air atmosphere of 450℃ for calcination for 1h. After calcination, cool it naturally, and use a 30W power laser to modify the surface lattice of the graphite felt with a 1.0mm aperture to obtain a graphite felt liquid flow battery electrode material.

[0091] Example 2 A method for preparing a graphite felt flow battery electrode material, the steps are as follows:

[0092] Take a graphite felt with a thickness of 4.35mm and a specification of 5cm×5cm, and use anhydrous ethanol to ultrasonically clean it at 420W for 0.5h. Place the cleaned graphite felt in a 60℃ oven and bake it for 0.5h, then soak it in a 0.5M sulfuric acid solution at 80℃ for 1.5h, take out the graphite felt and rinse it with ultrapure water until the pH value of the washing liquid is 6.5, then place the graphite felt in an 80℃ oven and bake it for 0.5h, take it out and place it in a muffle furnace with an air atmosphere of 450℃ for calcination for 1h. After calcination, cool it naturally, and use a 30W power laser to modify the surface lattice of the graphite felt with a 1.5mm aperture to obtain a graphite felt liquid flow battery electrode material.

[0093] Example 3 A method for preparing a graphite felt flow battery electrode material, the steps are as follows:

[0094] Take a graphite felt with a thickness of 4.35mm and a specification of 5cm×5cm, and use anhydrous ethanol to ultrasonically clean it at 420W for 0.5h. Place the cleaned graphite felt in a 60℃ oven and bake it for 0.5h, then soak it in a 0.5M sulfuric acid solution at 80℃ for 1.5h, take out the graphite felt and rinse it with ultrapure water until the pH value of the washing liquid is 6.5, then place the graphite felt in an 80℃ oven and bake it for 0.5h, take it out and place it in a muffle furnace with an air atmosphere of 450℃ for calcination for 1h. After calcination, cool it naturally, and use a 30W power laser to modify the surface lattice of the graphite felt with a 2.0mm aperture to obtain a graphite felt liquid flow battery electrode material.

[0095] Example 4 A method for preparing a graphite felt flow battery electrode material, the steps are as follows:

[0096] Take a graphite felt with a thickness of 2.5mm and a specification of 5cm×5cm, and use anhydrous ethanol to ultrasonically clean it at 420W for 0.5h. Place the cleaned graphite felt in a 60℃ oven and bake it for 0.5h, then soak it in a 0.5M sulfuric acid solution at 80℃ for 1.5h, take out the graphite felt and rinse it with ultrapure water until the pH value of the washing liquid is 6.5, then place the graphite felt in an 80℃ oven and bake it for 0.5h, take it out and place it in a muffle furnace with an air atmosphere of 450℃ for calcination for 1h. After calcination, cool it naturally, and use a 30W power laser to modify the surface lattice of the graphite felt with a 1.0mm aperture to obtain a graphite felt liquid flow battery electrode material.

[0097] Comparative Example 1

[0098] The same as Example 1, except that: a 60W power laser is used to modify the surface of the graphite felt with a 1.5 mm aperture.

[0099] Comparative Example 2

[0100] The same as Example 1, except that: a 10W power laser is used to modify the surface of the graphite felt with a 1.5 mm aperture.

[0101] Comparative Example 3

[0102] Same as Example 1, except that the thickness of the graphite felt is 6 mm.

[0103] Comparative Example 4

[0104] Same as Example 1, except that the calcination temperature is 550°C.

[0105] Test Example 1

[0106] The contact angle and mechanical properties of the graphite felt flow battery electrode materials of Examples 1-3 were tested, with the untreated graphite felt raw material as a control. The results are shown in Tables 1 and Figure 1-Figure 4 shown.

[0107] Table 1 Test results of sample contact angle and mechanical properties

[0108]

[0109]

[0110] Test Example 2

[0111] The surface microstructure and 3D surface profile of the graphite felt flow battery electrode materials of Examples 1-3 were tested, with the untreated graphite felt raw material as a control. The results are as follows: Figure 5-Figure 8 shown.

[0112] Test Example 3

[0113] The graphite felt flow battery electrode material of Example 1-3 and untreated graphite felt were used as electrodes to assemble and prepare an all-vanadium flow battery. The proton exchange membrane used in the battery was the PEM-50 proton exchange membrane produced by Shenzhen General Hydrogen Energy Technology Co., Ltd. The battery electrolyte used in the test was a 3.5-valent all-vanadium flow battery electrolyte, in which the vanadium ion concentration was 1.7 mol / L and the sulfate ion concentration was 4.7 mol / L. The battery performance was tested, and the results were as follows: Fig. 9 shown.

[0114] Example 5 A method for preparing a carbon paper flow battery electrode material, the steps are as follows:

[0115] Take a carbon paper with a thickness of 240μm and a specification of 5cm×5cm, and use anhydrous ethanol to ultrasonically clean it for 0.5h at 420W. Place the cleaned carbon paper in a 60℃ oven for 0.5h, then soak it in a 0.5M sulfuric acid solution at 80℃ for 1.5h, take out the carbon paper and rinse it with ultrapure water until the pH value of the washing liquid is 6.5, then place the carbon paper in an 80℃ oven for 0.5h, take it out and place it in a muffle furnace with an air atmosphere of 450℃ for calcination for 1h. After calcination, cool it naturally, and use a 20W power laser to modify the surface lattice of the carbon paper with a 0.3mm pore size to obtain a carbon paper liquid flow battery electrode material.

[0116] Example 6 A method for preparing a carbon paper flow battery electrode material, the steps are as follows:

[0117] Take a carbon paper with a thickness of 240μm and a specification of 5cm×5cm, and use anhydrous ethanol to ultrasonically clean it for 0.5h at 420W. Place the cleaned carbon paper in a 60℃ oven and bake it for 0.5h, then soak it in a 0.5M sulfuric acid solution at 80℃ for 1.5h, take out the carbon paper and rinse it with ultrapure water until the pH value of the washing liquid is 6.5, then place the carbon paper in an 80℃ oven and bake it for 0.5h, take it out and place it in a muffle furnace with an air atmosphere of 450℃ for calcination for 1h. After calcination, cool it naturally, and use a 20W power laser to modify the surface of the carbon paper with a 0.4mm pore size to obtain a carbon paper liquid flow battery electrode material.

[0118] Example 7 A method for preparing a carbon paper flow battery electrode material, the steps are as follows:

[0119] Take a carbon paper with a thickness of 240μm and a specification of 5cm×5cm, use anhydrous ethanol, ultrasonically clean it for 0.5h at 420W, place the cleaned carbon paper in a 60℃ oven for 0.5h, then soak it in a 0.5M sulfuric acid solution at 80℃ for 1.5h, take out the carbon paper and rinse it with ultrapure water until the pH value of the washing liquid is 6.5, then place the carbon paper in an 80℃ oven for 0.5h, take it out and place it in a muffle furnace with an air atmosphere of 450℃ for calcination for 1h, cool it naturally after calcination, and use a 20W power laser to modify the surface of the carbon paper with a 0.5mm pore size to obtain a carbon paper liquid flow battery electrode material.

[0120] Test Example 4

[0121] The contact angle and mechanical properties of the carbon paper flow battery electrode materials of Examples 5-7 were tested, with the untreated carbon paper raw materials as a control. The results are shown in Tables 2 and Figure 10-13 shown.

[0122] Table 2 Test results of sample contact angle and mechanical properties

[0123] Contact angle,° Tensile strength(MPa) Control group 137.490±3.925 24.66±1.65 Example 5 130.795±4.572 24.35±1.42 Example 6 126.754±3.464 24.12±1.27 Example 7 100.125±3.373 24.07±1.96

[0124] Test Example 5

[0125] The surface microstructure and 3D surface profile of the carbon paper flow battery electrode materials of Examples 5-7 were tested, with the untreated carbon paper raw material as a control. The results are as follows: Figure 14-17 shown.

[0126] Example 8 A method for preparing a carbon cloth liquid flow battery electrode material, the steps are as follows:

[0127] A carbon cloth with a thickness of 0.65 mm and a specification of 5 cm×5 cm was taken, and ultrasonically cleaned with anhydrous ethanol at 420 W for 0.5 h. The cleaned carbon cloth was placed in a 60°C oven for 0.5 h, and then immersed in a 0.5 M sulfuric acid solution at 80°C for 1.5 h. The carbon cloth was taken out and rinsed with ultrapure water until the pH value of the washing liquid was 6.5. The carbon cloth was then placed in an 80°C oven for 0.5 h, taken out and placed in a muffle furnace in an air atmosphere of 450°C for calcination for 1 h. After calcination, the carbon cloth was naturally cooled, and a 30 W power laser was used to modify the surface lattice of the carbon cloth with a 0.3 mm pore size to obtain a carbon cloth liquid flow battery electrode material.

[0128] Example 9 A method for preparing a carbon cloth liquid flow battery electrode material, the steps are as follows:

[0129] A carbon cloth with a thickness of 0.65 mm and a specification of 5 cm×5 cm was taken, and ultrasonically cleaned with anhydrous ethanol at 420 W for 0.5 h. The cleaned carbon cloth was placed in a 60°C oven for 0.5 h, and then immersed in a 0.5 M sulfuric acid solution at 80°C for 1.5 h. The carbon cloth was taken out and rinsed with ultrapure water until the pH value of the washing liquid was 6.5. The carbon cloth was then placed in an 80°C oven for 0.5 h, taken out and placed in a muffle furnace in an air atmosphere of 450°C for calcination for 1 h. After calcination, the carbon cloth was naturally cooled, and a 30 W power laser was used to modify the surface lattice of the carbon cloth with a 0.4 mm pore size to obtain a carbon cloth liquid flow battery electrode material.

[0130] Example 10 A method for preparing a carbon cloth liquid flow battery electrode material, the steps are as follows:

[0131] A carbon cloth with a thickness of 0.65 mm and a specification of 5 cm×5 cm was taken, and ultrasonically cleaned with anhydrous ethanol at 420 W for 0.5 h. The cleaned carbon cloth was placed in a 60°C oven for 0.5 h, and then immersed in a 0.5 M sulfuric acid solution at 80°C for 1.5 h. The carbon cloth was taken out and rinsed with ultrapure water until the pH value of the washing liquid was 6.5. The carbon cloth was then placed in an 80°C oven for 0.5 h, taken out and placed in a muffle furnace in an air atmosphere of 450°C for calcination for 1 h. After calcination, the carbon cloth was naturally cooled, and a 30 W power laser was used to modify the surface lattice of the carbon cloth with a 0.5 mm pore size to obtain a carbon cloth liquid flow battery electrode material.

[0132] Test Example 6

[0133] The contact angle and mechanical properties of the carbon cloth flow battery electrode materials of Examples 8-10 were tested, with the untreated carbon paper raw material as a control. The results are shown in Tables 3 and Figure 18-Figure 21 shown.

[0134] Table 3 Test results of sample contact angle and mechanical properties

[0135] Contact angle,° Tensile strength(MPa) Control group 123.524±3.609 3.98±0.26 Example 8 100.435±3.896 3.76±0.14 Example 9 100.536±3.244 3.55±0.22 Example 10 87.039±2.413 3.21±0.28

[0136] Test Example 7

[0137] The surface microstructure and 3D surface profile of the carbon cloth flow battery electrode materials of Examples 8-10 were tested, with the untreated carbon paper raw material as a control. The results are as follows: Figure 22-Figure 25 shown.

[0138] Embodiment 11

[0139] Same as Example 1, except that the thickness of the graphite felt is 3 mm. After testing, the contact angle of the obtained graphite felt flow battery electrode material is (93.644±3.005)°, and the tensile strength is not significantly different from that of the untreated 3 mm graphite felt (P>0.05).

[0140] Example 12

[0141] Same as Example 1, except that the thickness of the graphite felt is 4 mm. After testing, the contact angle of the obtained graphite felt flow battery electrode material is (93.056±2.816)°, and the tensile strength is not significantly different from that of the untreated 4 mm graphite felt (P>0.05).

[0142] Embodiment 13

[0143] Same as Example 1, except that the thickness of the graphite felt is 5 mm. After testing, the contact angle of the obtained graphite felt flow battery electrode material is (93.854±2.964)°, and the tensile strength is not significantly different from that of the untreated 5 mm graphite felt (P>0.05).

[0144] Embodiment 14

[0145] Same as Example 5, except that the thickness of the carbon paper is 450 μm. After testing, the contact angle of the obtained carbon paper flow battery electrode material is (131.002±3.642)°, and the tensile strength is not significantly different from that of the untreated 450 μm carbon paper (P>0.05).

[0146] Embodiment 15

[0147] Same as Example 5, except that the thickness of the carbon paper is 310 μm. After testing, the contact angle of the obtained carbon paper flow battery electrode material is (130.887±4.237)°, and the tensile strength is not significantly different from that of the untreated 310 μm carbon paper (P>0.05).

[0148] Example 16

[0149] Same as Example 5, except that the thickness of the carbon paper is 190 μm. After testing, the contact angle of the obtained carbon paper flow battery electrode material is (130.926±3.641)°, and the tensile strength is not significantly different from that of the untreated 190 μm carbon paper (P>0.05).

[0150] Embodiment 17

[0151] Same as Example 8, except that the thickness of the carbon cloth is 0.2 mm. After testing, the contact angle of the obtained carbon cloth liquid flow battery electrode material is (100.964±3.271), and the tensile strength is not significantly different from that of the untreated 0.2 mm carbon cloth (P>0.05).

[0152] Embodiment 18

[0153] Same as Example 8, except that the thickness of the carbon cloth is 0.3 mm. After testing, the contact angle of the obtained carbon cloth liquid flow battery electrode material is (100.467±4.164), and the tensile strength is not significantly different from that of the untreated 0.3 mm carbon cloth (P>0.05).

[0154] Embodiment 19

[0155] Same as Example 8, except that the thickness of the carbon cloth is 0.4 mm. After testing, the contact angle of the obtained carbon cloth liquid flow battery electrode material is (100.029±3.922), and the tensile strength is not significantly different from that of the untreated 0.4 mm carbon cloth (P>0.05).

[0156] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for preparing a carbon material flow battery electrode, characterized in that: The following steps are involved: S1. Add the carbon material into anhydrous ethanol and perform ultrasonic cleaning. After cleaning, dry the carbon material to remove impurities such as oil on the surface of the carbon material; S2, soaking the dried carbon material in an acid solution for acid treatment, and after the treatment, washing with ultrapure water until the pH value of the washing solution is 5-7; S3, drying and roasting the acid-treated carbon material, and cooling it naturally after roasting for later use; S4, performing laser surface lattice modification on the carbon material to obtain a carbon material flow battery electrode material; The thickness of the carbon material is 0.2-5 mm; the roasting temperature in S3 is 300°C-500°C, the roasting time is 1-5 hours, and the roasting is carried out in an air atmosphere; the laser energy of the laser surface lattice modification in step S4 is 10-50 W; the diameter of the lattice holes of the laser surface lattice modification is 0.3-5 mm.

2. The preparation method according to claim 1, characterized in that: The carbon material is graphite felt, carbon felt, carbon paper or carbon cloth.

3. The preparation method according to claim 1, characterized in that: In step S1, the ultrasonic cleaning time is 0.2 to 1 hour, and the ultrasonic power is 400 to 450W.

4. The preparation method according to claim 1, characterized in that: In step S1, the drying temperature is 40° C. to 80° C., and the drying time is 0.2 to 1 h.

5. The preparation method according to claim 1, characterized in that: In step S2, the acid treatment temperature is 60° C. to 100° C., and the acid treatment time is 0.5 to 5 hours.

6. The preparation method according to claim 1, characterized in that: In step S3, the drying temperature is 50° C. to 100° C., and the drying time is 0.5 to 1 hour.

7. The preparation method according to claim 1, characterized in that: The laser energy for laser surface lattice modification in step S3 is 30W.

8. The preparation method according to claim 1, characterized in that: The diameter of the lattice holes of the laser surface lattice modification in step S4 is 0.3-2 mm.

9. A carbon material flow battery electrode material, characterized in that: Prepared by the method according to any one of claims 1 to 8.

10. Use of the carbon material liquid flow battery electrode material according to claim 9 in the preparation of liquid flow batteries.

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