Preparation method of ruthenium dioxide-graphene-TALP thick dense electrode

Abstract

The application relates to a preparation method of a ruthenium dioxide-graphene-TALP thick dense electrode, and relates to a thick dense electrode preparation method. The application aims to solve the problem that the existing method cannot prepare a ruthenium dioxide-graphene thick dense electrode, and the application in supercapacitors is limited to a certain extent. The preparation method comprises the following steps: one, preparing a TALP dispersion solution; two, ultrasonic dispersion treatment of graphene nanosheets; three, hydrolysis preparation of a ruthenium dioxide-graphene nanosheet dispersion solution; four, preparation of a ruthenium dioxide-graphene-TALP nanosheet dispersion solution; and five, mechanical compaction preparation of a ruthenium dioxide-graphene-TALP thick dense electrode. The prepared ruthenium dioxide-graphene-TALP thick dense electrode has the characteristics of high compactness and thickness, excellent electrical conductivity and good volume capacitance performance, and can be used as an electrode for supercapacitors.

Description

Technical Field

[0001] This invention relates to a method for preparing a thick, dense electrode. Background Technology

[0002] As a green and environmentally friendly high-efficiency energy storage device, the performance of supercapacitors largely depends on the electrode materials used. Nanoscale electrode materials play a crucial role in making current electrochemical energy storage devices faster and lighter. However, due to the lower packing density and relatively lower volumetric performance of nanoscale materials, the volumetric capacitance of the devices is poor, preventing them from becoming smaller and significantly limiting their future applications.

[0003] Among numerous electrode materials, graphene possesses an extremely high specific surface area (2630 m²). 2 g -1 Extremely high electrical conductivity (10*6 S·m) -1 It possesses excellent thermal conductivity and mechanical properties, making it particularly suitable as an energy storage material, biomaterial, gas-sensitive material, superconductor, and conductive additive. Currently, methods to improve density mainly include: capillary evaporation drying, liquid-mediated compaction, processing of three-dimensional porous structures, and mechanical compaction.

[0004] While capillary drying and liquid-mediated compaction strategies can successfully fabricate dense electrodes, their thickness is too thin. Chemical activation methods for creating pores suffer from drawbacks such as low yield, limited micropore quantity, and excessively large pore size due to the need to clean residual activator on the material surface. Excessive pressure in mechanical compaction can cause material misshapenness. Therefore, considering practical applications, it is necessary to design electrodes with not only high volumetric capacity but also suitable electrode density and thickness. Currently, there are no reports in the literature on energy storage systems that simultaneously achieve high areal loading, high volumetric capacity, and high density. Summary of the Invention

[0005] The purpose of this invention is to solve the problem that existing methods cannot prepare ruthenium dioxide-graphene thick and dense electrodes, which limits their application in supercapacitors, and to provide a method for preparing ruthenium dioxide-graphene-TALP thick and dense electrodes.

[0006] This invention employs a simple electrostatic self-assembly method to successfully deposit ruthenium dioxide onto graphene nanosheets, adds a conductive binder TALP (tungstate-linked polyaniline) onto them, and then prepares a ruthenium dioxide-graphene-TALP thick electrode by vacuum filtration and mechanical compaction.

[0007] A method for preparing a ruthenium dioxide-graphene-TALP thick and dense electrode is specifically carried out according to the following steps:

[0008] I. Preparation of TALP dispersion:

[0009] ① Dissolve aniline in an aqueous sulfuric acid solution to obtain solution A;

[0010] ② Dissolve ammonium metatungstate and ammonium persulfate in deionized water to obtain solution B;

[0011] ③ Mix solution A and solution B, stir continuously at room temperature for a period of time, and then filter to obtain a solid substance; wash the solid substance and then vacuum dry it to obtain TALP powder; disperse the TALP powder in deionized water to obtain a TALP dispersion.

[0012] II. Ultrasonic Dispersion Treatment of Graphene Nanosheets:

[0013] ① Dissolve sodium lignosulfonate in deionized water to obtain sodium lignosulfonate solution; disperse graphene aqueous solution into sodium lignosulfonate solution under ultrasound, and disperse under ultrasound for a period of time to obtain graphene nanosheets treated with sodium lignosulfonate.

[0014] ② The graphene nanosheets treated with sodium lignosulfonate were washed and then dispersed in deionized water under ultrasonic conditions for a period of time to obtain a graphene nanosheet dispersion.

[0015] III. Preparation of Ruthenium Dioxide-Graphene Nanosheet Dispersion by Hydrolysis:

[0016] RuCl3 aqueous solution was mixed with graphene nanosheet dispersion, heated to 310℃~330℃, and then stirred and heated for a period of time under the conditions of stirring and temperature of 310℃~330℃ to obtain ruthenium dioxide-graphene nanosheet dispersion.

[0017] IV. Preparation of Ruthenium Dioxide-Graphene-TALP Nanosheet Dispersion:

[0018] The TALP dispersion and the ruthenium dioxide-graphene nanosheet dispersion were ultrasonically mixed for a period of time to obtain the ruthenium dioxide-graphene-TALP nanosheet dispersion.

[0019] V. Preparation of Ruthenium Dioxide-Graphene-TALP Thick Electrode by Mechanical Compaction:

[0020] ① The ruthenium dioxide-graphene-TALP nanosheet dispersion was filtered to form a membrane, then dried, and the membrane was peeled off to obtain the membrane electrode.

[0021] ② The membrane electrode is heat-treated at 140℃~160℃ for a period of time and then compacted to obtain a ruthenium dioxide-graphene-TALP thick and dense electrode.

[0022] Advantages of this invention:

[0023] I. This invention employs a simple electrostatic self-assembly method to successfully deposit and anchor ruthenium dioxide onto graphene nanosheets, adds a conductive binder TALP on top, and then prepares a ruthenium dioxide-graphene-TALP thick and dense electrode by vacuum filtration and mechanical compaction. The process is simple, feasible, and low in cost.

[0024] II. This invention overcomes the limitation of ruthenium dioxide-graphene itself in forming thick, dense electrodes by introducing high-quality, high-conductivity, and adhesive TALP into ruthenium dioxide-graphene, while also exhibiting excellent electrochemical performance. Experimental results show that at a current density of 1 A / g, the highest mass specific capacity is 201 F / g, and the highest volumetric specific capacity is 663 F / cm³. 3 As a well-formed self-supporting electrode, it meets the practical requirements of both ultra-high volumetric capacity and density, and has excellent prospects for superelectric applications. Attached Figure Description

[0025] Figure 1 These are physical images of ruthenium dioxide-graphene and the ruthenium dioxide-graphene-TALP thick electrode prepared in Example 1. Figure 1 In the diagram, a represents ruthenium dioxide-graphene, and b represents the ruthenium dioxide-graphene-TALP thick electrode prepared in Example 1.

[0026] Figure 2 These are scanning electron microscope images and spot scan patterns of the ruthenium dioxide-graphene-TALP thick electrode prepared in Example 1.

[0027] Figure 3 The X-ray diffraction patterns are those of the TALP, ruthenium dioxide-graphene, and ruthenium dioxide-graphene-TALP thick electrodes prepared in Example 1.

[0028] Figure 4 The images show the transmission electron microscope (TEM) image and surface scan image of the ruthenium dioxide-graphene-TALP thick electrode prepared in Example 1.

[0029] Figure 5 The image shows the CV curves of the ruthenium dioxide-graphene-TALP thick electrode prepared in Example 1 at different scan rates.

[0030] Figure 6 The image shows the GCD of the ruthenium dioxide-graphene-TALP thick electrode prepared in Example 1 at different current densities. Detailed Implementation

[0031] Specific Implementation Method 1: This implementation method describes a method for preparing a ruthenium dioxide-graphene-TALP thick electrode, which is specifically completed according to the following steps:

[0032] I. Preparation of TALP dispersion:

[0033] ① Dissolve aniline in an aqueous sulfuric acid solution to obtain solution A;

[0034] ② Dissolve ammonium metatungstate and ammonium persulfate in deionized water to obtain solution B;

[0035] ③ Mix solution A and solution B, stir continuously at room temperature for a period of time, and then filter to obtain a solid substance; wash the solid substance and then vacuum dry it to obtain TALP powder; disperse the TALP powder in deionized water to obtain a TALP dispersion.

[0036] II. Ultrasonic Dispersion Treatment of Graphene Nanosheets:

[0037] ① Dissolve sodium lignosulfonate in deionized water to obtain sodium lignosulfonate solution; disperse graphene aqueous solution into sodium lignosulfonate solution under ultrasound, and disperse under ultrasound for a period of time to obtain graphene nanosheets treated with sodium lignosulfonate.

[0038] ② The graphene nanosheets treated with sodium lignosulfonate were washed and then dispersed in deionized water under ultrasonic conditions for a period of time to obtain a graphene nanosheet dispersion.

[0039] III. Preparation of Ruthenium Dioxide-Graphene Nanosheet Dispersion by Hydrolysis:

[0040] RuCl3 aqueous solution was mixed with graphene nanosheet dispersion, heated to 310℃~330℃, and then stirred and heated for a period of time under the conditions of stirring and temperature of 310℃~330℃ to obtain ruthenium dioxide-graphene nanosheet dispersion.

[0041] IV. Preparation of Ruthenium Dioxide-Graphene-TALP Nanosheet Dispersion:

[0042] The TALP dispersion and the ruthenium dioxide-graphene nanosheet dispersion were ultrasonically mixed for a period of time to obtain the ruthenium dioxide-graphene-TALP nanosheet dispersion.

[0043] V. Preparation of Ruthenium Dioxide-Graphene-TALP Thick Electrode by Mechanical Compaction:

[0044] ① The ruthenium dioxide-graphene-TALP nanosheet dispersion was filtered to form a membrane, then dried, and the membrane was peeled off to obtain the membrane electrode.

[0045] ② The membrane electrode is heat-treated at 140℃~160℃ for a period of time and then compacted to obtain a ruthenium dioxide-graphene-TALP thick and dense electrode.

[0046] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that: the mass ratio of aniline to the volume of the sulfuric acid aqueous solution in step one ① is (0.9g~1.0g):50mL; the concentration of the sulfuric acid aqueous solution in step one ① is 0.2mol / L. All other steps are the same as in Specific Implementation Method One.

[0047] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that: the mass ratio of ammonium metatungstate to deionized water in step one, step two is (2g-3g):50mL; the mass ratio of ammonium persulfate to deionized water in step one, step two is (3g-4g):50mL. Other steps are the same as in Specific Implementation Method One or Two.

[0048] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that: the volume ratio of solution A to solution B in step one, step three is 1:1; and the continuous stirring time in step one, step three is 22 to 26 hours. The other steps are the same as in Specific Implementation Methods One to Three.

[0049] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that: in step one to three, the solid material is washed with water 3 to 5 times; the vacuum drying temperature in step one to three is 70°C to 80°C, and the vacuum drying time is 22 to 26 hours; the mass ratio of TALP powder to deionized water in step one to three is 10 mg: 10 mL. Other steps are the same as in Specific Implementation Methods One to Four.

[0050] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in the following ways: the mass ratio of sodium lignosulfonate to deionized water in step two① is (0.1g~0.3g):50mL; the mass fraction of the graphene aqueous solution in step two① is 2%~4%; the mass ratio of sodium lignosulfonate to graphene aqueous solution in step two① is 1:(3~5); the ultrasonic dispersion power in step two① is 500W, and the ultrasonic dispersion time is 0.5h~1h. Other steps are the same as in Specific Implementation Methods One to Five.

[0051] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in the following ways: In step two ②, the graphene nanosheets treated with sodium lignosulfonate are washed 2 to 4 times with deionized water; the mass ratio of sodium lignosulfonate to deionized water in step two ① is (0.1g to 0.3g):(20mL to 30mL); and the ultrasonic dispersion time in step two ② is 0.5h to 1h. Other steps are the same as in Specific Implementation Methods One to Six.

[0052] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in the following ways: the concentration of the RuCl3 aqueous solution in step three is 0.1 mol / L; the volume ratio of the RuCl3 aqueous solution to the graphene nanosheet dispersion in step three is (15 mL to 20 mL):(20 mL to 30 mL); and the stirring and heating time in step three at 310°C to 330°C is 5 h to 7 h. Other steps are the same as in Specific Implementation Methods One to Seven.

[0053] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One to Eight in that: the ultrasonic mixing power in step four is 900W, and the ultrasonic mixing time is 5-10 minutes; the volume ratio of the TALP dispersion to the ruthenium dioxide-graphene nanosheet dispersion in step four is (9-11 mL):(80-100 mL). Other steps are the same as in Specific Implementation Methods One to Eight.

[0054] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Methods One through Nine in the following ways: the drying temperature in step five① is 50℃~70℃; the heat treatment time in step five② is 18h~20h; and the compaction rate in step five② is 30MPa / 1.54cm. 2 The compaction time is 5 to 8 minutes. Other steps are the same as those in specific implementation methods one through nine.

[0055] The beneficial effects of the present invention are verified using the following embodiments:

[0056] Example 1: A method for preparing a ruthenium dioxide-graphene-TALP thick electrode, specifically completed according to the following steps:

[0057] I. Preparation of TALP dispersion:

[0058] ① Dissolve 0.93g of aniline in 50mL of 0.2mol / L sulfuric acid aqueous solution to obtain solution A;

[0059] ② Dissolve 2.5g of ammonium metatungstate and 3.42g of ammonium persulfate in 50mL of deionized water to obtain solution B;

[0060] ③ Mix solution A and solution B, stir continuously at room temperature for 24 hours, then filter to obtain a solid substance; wash the solid substance 5 times with deionized water, then vacuum dry at 80℃ for 24 hours to obtain TALP powder; disperse the TALP powder in deionized water to obtain TALP dispersion.

[0061] The volume ratio of solution A to solution B mentioned in step 1③ is 1:1;

[0062] The mass ratio of TALP powder to deionized water in step 1③ is 10 mg: 10 mL.

[0063] II. Ultrasonic Dispersion Treatment of Graphene Nanosheets:

[0064] ① Dissolve 0.2g of sodium lignosulfonate in 50mL of deionized water to obtain a sodium lignosulfonate solution; disperse 0.8g of 3% (w / w) graphene aqueous solution into the sodium lignosulfonate solution under ultrasonication, and ultrasonically disperse for 0.5h at an ultrasonic power of 500W to obtain graphene nanosheets treated with sodium lignosulfonate.

[0065] ② The graphene nanosheets treated with sodium lignosulfonate were washed three times and then dispersed in 25 mL of deionized water under ultrasonic conditions for 0.5 h to obtain a graphene nanosheet dispersion.

[0066] III. Preparation of Ruthenium Dioxide-Graphene Nanosheet Dispersion by Hydrolysis:

[0067] 17 mL of 0.1 mol / L RuCl3 aqueous solution was mixed with graphene nanosheet dispersion, heated to 320 °C, and then stirred and heated at 320 °C for 6 h to obtain ruthenium dioxide-graphene nanosheet dispersion.

[0068] IV. Preparation of Ruthenium Dioxide-Graphene-TALP Nanosheet Dispersion:

[0069] The TALP dispersion and the ruthenium dioxide-graphene nanosheet dispersion were ultrasonically mixed for 5 min to obtain the ruthenium dioxide-graphene-TALP nanosheet dispersion (TALP content was 10%).

[0070] The power of the ultrasonic mixing described in step four is 900W;

[0071] The volume ratio of the TALP dispersion to the ruthenium dioxide-graphene nanosheet dispersion in step four is 10 mL: 90 mL.

[0072] V. Preparation of Ruthenium Dioxide-Graphene-TALP Thick Electrode by Mechanical Compaction:

[0073] ① The ruthenium dioxide-graphene-TALP nanosheet dispersion was filtered to form a membrane, then dried at 60°C, and the membrane was peeled off to obtain the membrane electrode.

[0074] ② The membrane electrode was heat-treated at 150℃ for 19h and then compacted for 5min to obtain a ruthenium dioxide-graphene-TALP thick and dense electrode (TALP-RuO2-Graphene(10% TALP)).

[0075] The compaction rate described in step 5② is 30 MPa / 1.54 cm. 2 .

[0076] Example 2: The ruthenium dioxide-graphene-TALP thick electrode prepared in Example 1 was used as the working electrode for electrochemical testing. The specific operation is as follows:

[0077] The ruthenium dioxide-graphene-TALP thick electrode prepared in Example 1 was used as the working electrode, a Pt sheet as the counter electrode, Hg / Hg2SO4 as the reference electrode, and a 1 mol / L H2SO4 solution as the electrolyte. The electrochemical performance of the ruthenium dioxide-graphene-TALP thick electrode prepared in Example 1 was tested using a conventional three-electrode system through cyclic voltammetry and constant current charge-discharge methods.

[0078] Figure 1 These are physical images of ruthenium dioxide-graphene and the ruthenium dioxide-graphene-TALP thick electrode prepared in Example 1. Figure 1 In the diagram, a represents ruthenium dioxide-graphene, and b represents the ruthenium dioxide-graphene-TALP thick electrode prepared in Example 1.

[0079] from Figure 1 It is evident that the addition of TALP allows the material to be compacted into a dense electrode.

[0080] Figure 2 These are scanning electron microscope images and spot scan patterns of the ruthenium dioxide-graphene-TALP thick electrode prepared in Example 1.

[0081] from Figure 2 As can be seen from the above, the ruthenium dioxide-graphene-TALP thick electrode prepared in Example 1 has a sheet-like structure; the graphene nanosheets have a smooth surface, the graphene sheets are thin and transparent, and the composite material contains elements such as C, O, Ru and W.

[0082] Figure 3 The X-ray diffraction patterns are those of the TALP, ruthenium dioxide-graphene, and ruthenium dioxide-graphene-TALP thick electrodes prepared in Example 1.

[0083] Figure 3 A diffraction peak corresponding to the (002) crystal plane of graphene appeared at 26.5° in the curve. A TALP diffraction peak also appeared. Since ruthenium dioxide is amorphous, the diffraction peaks are not obvious, but the presence of ruthenium can be clearly seen from both scanning electron microscopy and transmission electron microscopy, indicating that the composite material is composed of ruthenium dioxide, graphene, and TALP.

[0084] Figure 4 The images show the transmission electron microscope (TEM) image and surface scan image of the ruthenium dioxide-graphene-TALP thick electrode prepared in Example 1.

[0085] The distribution of five elements—C, O, N, W, and Ru—can be observed through surface scanning electron microscopy (SEM). The interlayer spacing of the HRTEM layer is 0.479 nm, indicating that the substance is TALP.

[0086] Figure 5 The image shows the CV curves of the ruthenium dioxide-graphene-TALP thick electrode prepared in Example 1 at different scan rates.

[0087] from Figure 5 It can be seen that the capacitance of the material decreases as the scanning rate increases.

[0088] Figure 6 The images show the GCD of the ruthenium dioxide-graphene-TALP thick electrode prepared in Example 1 at different current densities.

[0089] from Figure 6 It can be seen that the ruthenium dioxide-graphene-TALP thick electrode prepared in Example 1 has a mass specific capacity as high as 201 F / g and a volume specific capacity as high as 663 F / cm³ at a current density of 1 A / g. 3 As the rate of expansion increases, the performance remains well maintained; at a high rate of 20 A / g, the capacity remains at 217 F / cm³. 3 ,from Figure 6 It was clearly observed that the volumetric capacity of the composite material decreased with the increase of current density, with a decrease rate of 32.8%.

Claims

1. A method for preparing a ruthenium dioxide-graphene-TALP thick-density electrode, characterized in that... The ruthenium dioxide-graphene-TALP thick-density electrode exhibits a high specific capacity of 201 F / g and a high volumetric specific capacity of 663 F / cm³ at a current density of 1 A / g. 3 ; The preparation method is specifically carried out according to the following steps: I. Preparation of TALP dispersion: ① Dissolve 0.93g of aniline in 50mL of 0.2mol / L sulfuric acid aqueous solution to obtain solution A; ② Dissolve 2.5g of ammonium metatungstate and 3.42g of ammonium persulfate in 50mL of deionized water to obtain solution B; ③ Mix solution A and solution B, stir continuously at room temperature for 24 hours, then filter to obtain a solid substance; wash the solid substance 5 times with deionized water, then vacuum dry at 80℃ for 24 hours to obtain TALP powder; disperse the TALP powder in deionized water to obtain TALP dispersion. The volume ratio of solution A to solution B mentioned in step 1③ is 1:1; The mass ratio of TALP powder to deionized water in step 1③ is 10 mg: 10 mL. II. Ultrasonic Dispersion Treatment of Graphene Nanosheets: ① Dissolve 0.2g of sodium lignosulfonate in 50mL of deionized water to obtain a sodium lignosulfonate solution; disperse 0.8g of 3% (w / w) graphene aqueous solution into the sodium lignosulfonate solution under ultrasonication, and ultrasonically disperse for 0.5h at an ultrasonic power of 500W to obtain graphene nanosheets treated with sodium lignosulfonate. ② The graphene nanosheets treated with sodium lignosulfonate were washed three times and then dispersed in 25 mL of deionized water under ultrasonic conditions for 0.5 h to obtain a graphene nanosheet dispersion. III. Preparation of Ruthenium Dioxide-Graphene Nanosheet Dispersion by Hydrolysis: 17 mL of 0.1 mol / L RuCl3 aqueous solution was mixed with graphene nanosheet dispersion, heated to 320 °C, and then stirred and heated at 320 °C for 6 h to obtain ruthenium dioxide-graphene nanosheet dispersion. IV. Preparation of Ruthenium Dioxide-Graphene-TALP Nanosheet Dispersion: The TALP dispersion and the ruthenium dioxide-graphene nanosheet dispersion were ultrasonically mixed for 5 min to obtain the ruthenium dioxide-graphene-TALP nanosheet dispersion. The power of the ultrasonic mixing described in step four is 900W; The volume ratio of the TALP dispersion to the ruthenium dioxide-graphene nanosheet dispersion in step four is 10 mL: 90 mL. V. Preparation of Ruthenium Dioxide-Graphene-TALP Thick Electrode by Mechanical Compaction: ① The ruthenium dioxide-graphene-TALP nanosheet dispersion was filtered to form a membrane, then dried at 60°C, and the membrane was peeled off to obtain the membrane electrode. ② The membrane electrode was heat-treated at 150℃ for 19 hours and then compacted for 5 minutes to obtain a ruthenium dioxide-graphene-TALP thick electrode.

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