Preparation method and application of defect-rich crystalline ruo2 porous material

Abstract

The application discloses a preparation method and application of a defective crystalline RuO2 porous material. The defective crystalline RuO2 porous material is prepared by the following steps: coating a PS microsphere slurry on a high-purity tantalum foil as a current collector to form an electrode sheet, immersing the electrode sheet in a ruthenium source solution to adsorb Ru, and heat-treating the electrode sheet under certain conditions. The preparation method can reduce the complexity of a RuO2 positive electrode material process, is non-toxic, and the obtained nano-porous RuO2 has a larger surface area and more active sites, so that the hydrogen ions can be stored when the material is used as a water-based hydrogen storage electrode.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen storage materials technology, specifically relating to a defect-rich crystalline RuO2 porous material, its preparation method, and its application. Background Technology

[0002] As environmental pollution from fossil fuel use becomes increasingly severe, the utilization of clean energy is attracting more and more attention. However, the large-scale harvesting of intermittent and regional renewable energy requires efficient energy storage systems to store, distribute, and utilize electricity. Therefore, the demand for energy conversion and storage is also increasing, making optimized energy management and large-scale storage crucial. Proton batteries, with their rapid diffusion kinetics, are more environmentally friendly and safer, exhibiting significant competitiveness. Developing high-capacity hydrogen-ion battery cathode materials is of great importance. Nanoporous RuO2 materials are an ideal high-capacity hydrogen-ion battery cathode material, but current RuO2 material preparation methods are complex, costly, and have low capacity. Summary of the Invention

[0003] This invention is proposed to overcome the problems of easy agglomeration and low capacity of RuO2 materials during the recycling process in the prior art. Its purpose is to provide a defect-rich crystalline RuO2 porous material, its preparation method and application.

[0004] This invention is achieved through the following technical solution:

[0005] A method for preparing defect-rich crystalline RuO2 porous material includes the following steps:

[0006] (i) Cut high-purity tantalum foil with a purity of ≥99.5% and a thickness of 0.05mm into 1cm×2cm pieces;

[0007] (ii) The cut high-purity tantalum foil was ultrasonically cleaned in ethanol and deionized water respectively to remove surface oil and impurities, and then dried in an oven to complete the pretreatment of the high-purity tantalum foil.

[0008] (iii) Preparation of PS microsphere slurry: PS microspheres (polystyrene microspheres) and LA binder are mixed and ball-milled at a mass ratio of 9:1 to 7:3 for 8 hours. The mass concentration of LA binder is 5%, and the solvent of LA binder is water.

[0009] (iv) Using pretreated high-purity tantalum foil as a current collector, after uniformly coating with a slurry, it is dried in an oven at 60℃~70℃ for 8h~12h to obtain an electrode sheet; the coating amount of PS microsphere slurry is 1mg / cm³. 2 ~2mg / cm 2 ;

[0010] (v) Immerse the dried electrode in a 0.2 mol / L ruthenium source solution for 10 min to 30 min, remove and let stand for 30 min to 60 min, rinse with deionized water for 15 s to 30 s, and dry in an oven at 60 ℃ to 70 ℃ for 2 h to 3 h.

[0011] (vi) The electrode sheet after step (v) is placed in a muffle furnace and heat-treated at 300℃~650℃ for 2h~3h to obtain a defect-rich crystalline RuO2 porous material supported by tantalum foil.

[0012] In the above technical solution, the optimal conditions for the oven drying process in step (iv) are 60°C for 8 hours.

[0013] In the above technical solution, the optimal conditions for heat treatment in step (vi) are heat treatment at 300°C for 3 hours.

[0014] In the above technical solution, the ruthenium source solution is a methanol solution of hydrated ruthenium chloride; the solute of the methanol solution of hydrated ruthenium chloride is hydrated ruthenium chloride, the solvent is methanol, and the solute concentration is 0.1mol / L to 0.2mol / L; the soaking time in step (v) is preferably 10min; the standing time is preferably 30min; and the rinsing time with deionized water is preferably 30s.

[0015] A defect-rich crystalline RuO2 porous material was prepared by the above method. The defect richness is manifested in the pores, and the crystalline characteristics can be seen from the XRD data.

[0016] A method for hydrogen ion storage using defect-rich crystalline RuO2 porous materials involves using the defect-rich crystalline RuO2 porous electrode material as the working electrode, a graphite rod or platinum wire as the counter electrode, and a saturated calomel electrode as the reference electrode, forming a three-electrode system. This system is then used to store hydrogen ions with a certain concentration of H2. + An aqueous proton storage half-cell was assembled using a 0.5 mol / L sulfuric acid electrolyte to store hydrogen ions in a reaction vessel. The three-electrode system operates at a voltage window of 0V–1V (compared to a saturated calomel electrode) and a temperature range of 10℃–60℃.

[0017] The beneficial effects of this invention are:

[0018] This invention provides a defect-rich crystalline RuO2 porous material, its preparation method, and its applications. A defect-rich crystalline RuO2 cathode material with a nanoporous structure is prepared using an impregnation heat treatment method. This preparation method reduces the complexity of RuO2 cathode material processing and is non-toxic. The resulting nanoporous RuO2 has a larger surface area, effectively increasing the specific surface area and conductivity of ruthenium dioxide particles, and providing numerous active reaction sites. Using this material as an aqueous hydrogen storage electrode enables hydrogen ion storage. This invention primarily focuses on preparing nanoporous RuO2 materials as cathodes in aqueous hydrogen-ion batteries, exhibiting excellent electrochemical energy storage performance, including high specific capacitance. This invention has broad feasibility and is applicable to various aqueous ion electrolytes, providing conditions for subsequent large-scale preparation and commercial applications, and has significant application value in hydrogen storage electrode preparation. Attached Figure Description

[0019] Figure 1 This is a SEM image of the defect-rich crystalline RuO2 porous material prepared in Example 1 of this invention;

[0020] Figure 2 This is a SEM image of the defect-rich crystalline RuO2 porous material prepared in Example 2 of this invention;

[0021] Figure 3 This is a SEM image of the defect-rich crystalline RuO2 porous material prepared in Example 3 of this invention;

[0022] Figure 4 This is a SEM image (magnified 5000 times) of the defect-rich crystalline RuO2 porous material prepared in Example 3 of the present invention;

[0023] Figure 5 This is the XRD pattern of the defect-rich crystalline RuO2 porous material prepared in Example 3 of this invention;

[0024] Figure 6 This is a CV test image of the defect-rich crystalline RuO2 porous material prepared in Example 3 of the present invention in H2SO4 solution;

[0025] Figure 7 This is the calculated mass capacity of the defect-rich crystalline RuO2 porous material prepared in Example 3 of this invention.

[0026] For those skilled in the art, other related figures can be obtained from the above figures without any creative effort. Detailed Implementation

[0027] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0028] Example 1

[0029] A method for preparing defect-rich crystalline RuO2 porous materials by impregnation heat treatment to achieve H + The storage method is as follows:

[0030] (i) Cut high-purity tantalum foil with a purity of ≥99.5% and a thickness of 0.05mm into 1cm×2cm pieces;

[0031] (ii) High-purity tantalum foil was ultrasonically cleaned with ethanol and deionized water respectively to remove surface oil and impurities, and then dried.

[0032] (iii) Prepare a slurry of PS microspheres:LA binder = 9:1 and ball mill it for 8 hours;

[0033] (iv) The high-purity tantalum foil processed in step (ii) is used as a current collector, and the slurry prepared in step (iii) is uniformly coated on it and dried in an oven at 60°C for 8 hours.

[0034] (v) Prepare a 0.2 mol / L hydrated ruthenium chloride-methanol solution;

[0035] (ⅵ) Immerse the electrode sheet obtained in step (ⅳ) in the solution of step (ⅴ) for 10 min, take it out and let it stand for 30 min, rinse it with deionized water for 30 s, and dry it in an oven at 60 ℃.

[0036] (vii) The obtained material was placed in a muffle furnace and heat-treated at 300°C for 3 hours to obtain a defect-rich crystalline RuO2 porous material;

[0037] (ⅷ) Prepare 0.5 mol / L (H2O) + A sulfuric acid electrolyte with a concentration of ( );

[0038] (ⅸ) Assemble an aqueous hydrogen storage half-cell: In H + In a sulfuric acid electrolyte with a concentration of 0.5 mol / L, the defect-rich crystalline RuO2 porous material obtained in step (vii) is used as the working electrode, a saturated calomel electrode is used as the reference electrode, and a platinum wire is used as the counter electrode to form an electrode system at room temperature, and hydrogen ions are stored in a reaction vessel.

[0039] Example 2

[0040] Based on Example 1, the only difference between this example and Example 1 is that the ratio of PS microspheres to LA binder in step (iii) is 8:2.

[0041] Example 3

[0042] Based on Example 1, the only difference between this example and Example 1 is that the heat treatment temperature in step (vii) is 650°C and the time is 3 hours.

[0043] Testing and Characterization:

[0044] (a) SEM test

[0045] SEM test results show that Figure 1 , 2 Images 1 and 3 are scanning electron microscope images of the materials prepared in Examples 1-3 at 20,000x magnification. Figure 4 The image shows a scanning electron microscope (SEM) image of the product prepared in Example 3 at 5000x magnification. As can be seen from the image, a nanoporous RuO2 structure is formed on the tantalum surface after heat treatment. Furthermore, with the improvement of the experimental method, the porous structure becomes more regular and uniform, with a diameter of approximately 1.25 μm.

[0046] (b) XRD test

[0047] XRD test results are as follows Figure 5 As shown, it can be demonstrated that the product of Example 3 after high-temperature heat treatment has a crystal structure, and its peak position is consistent with that of the RuO2 standard card.

[0048] (c) Electrochemical testing

[0049] Figure 6 The CV test curve of the defect-rich crystalline RuO2 porous material prepared in Example 3 in H2SO4 solution is shown below. Figure 6 It can be seen that RuO2 has a typical rectangular CV curve for pseudocapacitance, and the mass capacity of the sample can be obtained by the area of ​​the CV curve, indicating that RuO2 has a high capacity.

[0050] Figure 7 To measure the mass capacity of the defect-rich crystalline RuO2 porous material prepared in Example 3 at different scan rates, the test conditions were as follows: in a 0.5 mol / L H2SO4 solution, the working electrode was RuO2 nanoporous material, the counter electrode was a platinum wire electrode, and the reference electrode was a saturated calomel electrode. Figure 7 It can be seen that even at high scan rates, RuO2 still has high capacity and good rate performance.

[0051] In this invention, the PS microsphere slurry provides template support; the ruthenium source solution uses methanol as a solvent to help ruthenium better penetrate the template and adsorb onto the PS microsphere surface; the tantalum foil serves to carry the active material throughout the synthesis process, and the tantalum remains intact at the end. The entire synthesis process mainly involves adsorbing the active material using the template, and finally etching away the template to retain the framework structure. The chemical reaction equation involved in the heat treatment process is RuCl3 + O2 → RuO2 + Cl2.

[0052] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0053] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a defect-rich crystalline RuO2 porous material, characterized in that: (i) Preparation of electrode sheets PS microsphere slurry was uniformly coated onto the surface of pretreated high-purity tantalum foil. After coating, the slurry was dried to obtain the electrode sheet. The coating amount of the PS microsphere slurry is 1 mg / cm³. 2 ~2mg / cm 2 ; The PS microsphere slurry was obtained by ball milling a mixture of PS microspheres and LA binder at a mass ratio of 9:1 to 7:3 for 8 hours; the mass concentration of the LA binder was 5%. (ii) Immerse the electrode sheet prepared in step (i) in a ruthenium source solution, remove it after immersion and let it stand, then clean and dry it; the ruthenium source solution is a methanol solution of hydrated ruthenium chloride; the solute of the methanol solution of hydrated ruthenium chloride is hydrated ruthenium chloride, the solvent is methanol, and the solute concentration is 0.1mol / L~0.2mol / L; The soaking time in step (ii) is 10 min to 30 min, the standing time is 30 min to 60 min, the rinsing is done with deionized water for 15 s to 30 s, the drying temperature is 60 ℃ to 70 ℃, and the drying time is 2 h to 3 h. (iii) Heat-treat the electrode sheet after step (ii) to obtain a defect-rich crystalline RuO2 porous material supported by tantalum foil.

2. The method for preparing defect-rich crystalline RuO2 porous material according to claim 1, characterized in that: The high-purity tantalum foil has a purity of ≥99.5% and a thickness of 0.05 mm. The pretreatment method for the high-purity tantalum foil is as follows: the high-purity tantalum foil is ultrasonically cleaned in ethanol and deionized water respectively to remove surface oil and impurities, and then dried in an oven.

3. The method for preparing defect-rich crystalline RuO2 porous material according to claim 1, characterized in that: The drying process in step (i) is carried out at a temperature of 60℃~70℃ for a duration of 8h~12h.

4. The method for preparing defect-rich crystalline RuO2 porous material according to claim 1, characterized in that: In step (iii), the heat treatment temperature is 300℃~650℃, the heat treatment duration is 2h~3h, and the heat treatment atmosphere is air.

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