Hydrogen molybdenum bronze nanosheet material, preparation method and application of hydrogen molybdenum bronze nanosheet material in low-temperature proton energy storage

Abstract

The invention discloses a hydrogen molybdenum bronze nanosheet material, a preparation method and application of the hydrogen molybdenum bronze nanosheet material in low-temperature proton energy storage. And reacting the MoO3 suspension with a Na2S2O4 solution to obtain a product, further mixing and stirring the product with an HCl aqueous solution, filtering, washing, and drying to obtain the hydrogen molybdenum bronze nanosheet material. The hydrogen-molybdenum bronze material can be applied to a low-temperature proton hybrid capacitor, has high specific capacity, excellent rate capability and good low-temperature performance, has a working temperature range of-80 to 25 DEG C, and is particularly suitable for being applied to low-temperature proton energy storage.

Description

Technical Field

[0001] The present invention belongs to the field of electrochemical energy storage, and specifically relates to a hydrogen-molybdenum-bronze nanosheet material, a preparation method and application thereof in low-temperature proton energy storage. Background Art

[0002] The strong bonding of metal ions in lithium-ion battery materials inhibits the kinetics of ion transport, leading to bottlenecks such as insufficient power and safety imbalance that are difficult to overcome. + Due to their lowest ionic mass and smallest ionic radius, proton hybrid capacitors (PHCs) possess higher specific capacity and faster kinetics than metal ions, enabling rapid migration even at low temperatures. Proton hybrid capacitors (PHCs) are energy storage devices that use protons as payload ions. They overcome the power limitations of traditional metal-ion batteries and the energy limitations of capacitors, combining the advantages of both.

[0003] Current research on proton energy storage electrode materials has largely focused on Ti-, Mo-, and W-based anode materials with layered and tunneling crystal structures (such as MoO3 and WO3) and defective open-framework hydrated Prussian blue analogs (such as copper- and vanadium-based Prussian blue) cathode materials. However, current electrode materials for proton hybrid capacitors face severe capacity fading issues in extreme environments such as high power and ultra-low temperatures. Furthermore, key mechanisms such as ion transport in electrode materials under extreme conditions remain unclear, necessitating the development of new, broadly applicable electrode material design strategies. Summary of the Invention

[0004] The present invention aims to provide a hydrogen-molybdenum-bronze nanosheet material, a preparation method thereof, and its application in low-temperature proton energy storage. By improving the synthesis method of hydrogen-molybdenum-bronze and optimizing its crystal structure, the present invention enables the hydrogen-molybdenum-bronze nanosheet material to be used as a negative electrode material in proton hybrid capacitors, thereby achieving higher specific capacity, excellent rate performance, longer cycle life, and good low-temperature performance, thereby solving the low capacity and rate problems of existing electrode materials in high-power and ultra-low-temperature conditions.

[0005] In order to solve the problems of the prior art, the technical solution adopted by the present invention is:

[0006] A preparation method for a hydrogen-molybdenum bronze nanosheet material comprises the following steps: adding MoO3 particles to deionized water and continuously stirring to form a MoO3 slurry; dissolving Na2S2O4 in deionized water to prepare a Na2S2O4 solution; and adding the Na2S2O4 solution to the MoO3 slurry under rapid stirring to initiate a reaction, wherein the molar ratio of MoO3 to Na2S2O4 is 3:1, and the color of the reaction slurry changes from white to purple. After continuous rapid stirring for 1 to 8 hours, solid powder is collected and placed in a 1M HCl aqueous solution and rapidly stirred for 6 hours, and then filtered, washed, and dried to obtain the hydrogen-molybdenum bronze nanosheet material.

[0007] Preferably, the MoO3 particles are orthorhombic molybdenum trioxide particles, and the particle size is less than 10 μm.

[0008] The hydrogen-molybdenum-bronze nanosheet material prepared by any of the above preparation methods contains crystal water in its structure.

[0009] Preferably, the thickness of the nanosheet is 10 nm to 50 nm, and the length is 1 μm to 5 μm.

[0010] The above-mentioned hydrogen-molybdenum-bronze nanosheet material is used as an electrode in a proton hybrid capacitor.

[0011] A hydrogen-molybdenum-bronze material electrode sheet contains the above-mentioned hydrogen-molybdenum-bronze nanosheet material.

[0012] Preferably, the preparation method of the above-mentioned hydrogen-molybdenum bronze material electrode sheet comprises the following steps: hydrogen-molybdenum bronze nanosheets are used as active materials, mixed evenly with Ketjen black and polyvinylidene fluoride to obtain a mixture, and then N-methylpyrrolidone is added dropwise to the mixture to form a slurry, and then the slurry is evenly coated on the surface of carbon paper, and dried to obtain a hydrogen-molybdenum bronze material electrode sheet.

[0013] Preferably, the operating temperature of the hydrogen-molybdenum-bronze nanosheet electrode is -80 to 25°C.

[0014] Beneficial effects:

[0015] Compared with the prior art, the hydrogen-molybdenum bronze nanosheet material, preparation method, and application in low-temperature proton energy storage of the present invention have the following advantages:

[0016] (1) The hydrogen molybdenum bronze nanosheet material prepared by the present invention has a maximum specific capacitance of up to 405 mAh g -1 When the current density is 100A·g -1 When the specific capacity is 227mAh·g -1 , with excellent specific capacity and rate performance.

[0017] (2) The hydrogen-molybdenum bronze nanosheet material prepared by the present invention has a unique nanosheet microstructure that can effectively improve electrochemical performance. The abundant crystal water and increased interlayer spacing can provide higher electronic conductivity and ion diffusivity.

[0018] (3) The hydrogen-molybdenum-bronze nanosheet electrode prepared by the present invention can work efficiently in the range of -80 to 25°C. Among them, the maximum capacity at the ultra-low temperature of -80°C is 194 mAh·g -1 , which can meet the use requirements of proton hybrid capacitors in low temperature environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 X-ray diffraction patterns of the hydrogen molybdenum bronze nanosheet material of Example 1 of the present invention and the material of Comparative Example 1;

[0020] Figure 2 The scanning electron microscope image and the transmission electron microscope image of the hydrogen molybdenum bronze nanosheet material of Example 1 of the present invention are shown;

[0021] Figure 3 The solid-state nuclear magnetic H spectra of the hydrogen molybdenum bronze nanosheet material of Example 1 of the present invention and the material of Comparative Example 1;

[0022] Figure 4 This is a constant current charge and discharge curve diagram of the electrode prepared from the hydrogen molybdenum bronze nanosheet material of Example 1 of the present invention at different current densities;

[0023] Figure 5 This is a comparison chart of the capacity of the electrode prepared from the hydrogen-molybdenum-bronze nanosheet material of Example 1 of the present invention at different temperatures;

[0024] Figure 6 This is a constant current charge and discharge curve diagram of the electrode prepared from the hydrogen-molybdenum-bronze nanosheet material of Example 1 of the present invention at -80°C. DETAILED DESCRIPTION

[0025] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0026] A preparation method of a hydrogen-molybdenum bronze nanosheet material comprises the following steps: adding MoO3 particles into deionized water and continuously stirring to form a MoO3 slurry; dissolving Na2S2O4 in deionized water to prepare a Na2S2O4 solution; and adding the Na2S2O4 solution to the MoO3 slurry under rapid stirring to initiate a reaction, wherein the molar ratio of MoO3 to Na2S2O4 is 3:1, and the color of the reaction slurry changes from white to purple. After continuous rapid stirring for 1 to 8 hours, solid powder is collected and placed in a 1M HCl aqueous solution and rapidly stirred for 6 hours, and then filtered, washed, and dried to obtain the hydrogen-molybdenum bronze nanosheet material.

[0027] Preferably, the MoO3 particles are orthorhombic molybdenum trioxide particles, and the particle size is less than 10 μm.

[0028] The hydrogen-molybdenum-bronze nanosheet material prepared by the above method contains crystal water in its structure.

[0029] Preferably, the thickness of the nanosheet is 10 nm to 50 nm, and the length is 1 μm to 5 μm.

[0030] The above-mentioned hydrogen-molybdenum-bronze nanosheet material is used as an electrode in a proton hybrid capacitor.

[0031] A hydrogen-molybdenum-bronze material electrode sheet contains the above-mentioned hydrogen-molybdenum-bronze nanosheet material.

[0032] Preferably, the preparation method of the above-mentioned hydrogen-molybdenum bronze material electrode sheet comprises the following steps: hydrogen-molybdenum bronze nanosheets are used as active materials, mixed evenly with Ketjen black and polyvinylidene fluoride to obtain a mixture, and then N-methylpyrrolidone is added dropwise to the mixture to form a slurry, and then the slurry is evenly coated on the surface of carbon paper, and dried to obtain a hydrogen-molybdenum bronze material electrode sheet.

[0033] Preferably, the operating temperature of the hydrogen-molybdenum-bronze nanosheet electrode is -80 to 25°C.

[0034] It should be pointed out that the specific contents involved in the embodiments of the present application can be found in the description of the above embodiments. For the sake of brevity, they will not be repeated here.

[0035] For ease of understanding, the technical solutions provided in this application are described in detail below in conjunction with specific embodiments.

[0036] Example 1

[0037] A method for preparing a hydrogen-molybdenum bronze nanosheet material comprises the following steps:

[0038] Step 1, prepare MoO3 suspension:

[0039] 5 g of MoO3 particles with a particle size of less than 10 μm were weighed and added to 100 mL of deionized water. The mixture was rapidly stirred at 500 rpm for 30 min under magnetic stirring to obtain a uniform MoO3 suspension.

[0040] Step 2, prepare Na2S2O4 solution:

[0041] Weigh 2 g of Na2S2O4 powder, dissolve it in 100 mL of deionized water, and stir rapidly at 500 rpm under magnetic stirring for 30 min to obtain a uniform Na2S2O4 solution.

[0042] Step 3, mixed solution reaction:

[0043] The Na2S2O4 solution was slowly added to the MoO3 suspension and rapidly stirred at room temperature for 6 h. After the reaction was completed, the product was filtered, washed and dried to obtain the product.

[0044] Step 4, product post-processing:

[0045] 750 mg of the above product was added to 100 mL of 1 M HCl aqueous solution, and the mixture was rapidly stirred at 500 rpm at room temperature for 6 hours. The mixture was filtered, washed, and dried to obtain hydrogen molybdenum bronze nanosheet material.

[0046] Figure 1 In the X-ray diffraction pattern of the hydrogen-molybdenum bronze provided in this embodiment, the main diffraction peaks form new split peaks, indicating that the crystal phase of the product is a protonated hydrogen-molybdenum bronze structure.

[0047] Figure 2 The scanning electron microscope image and transmission electron microscope image of the hydrogen molybdenum bronze nanosheet provided in this embodiment have obvious nanosheet morphology structure, thickness of 20nm to 50nm, and length of 1μm to 5μm.

[0048] Figure 3 In the solid-state nuclear magnetic resonance (H) spectrum of hydrogen molybdenum bronze provided in this embodiment, the peaks at chemical shifts of 6.97, 5.56, and 1.13 ppm are generated by adsorbed water, lattice water, and lattice hydroxyl groups, respectively.

[0049] The above hydrogen molybdenum bronze nanosheet material is prepared into an electrode sheet in the following steps:

[0050] Hydrogen-molybdenum bronze nanosheets, Ketjen black, and polyvinylidene fluoride (PVDF) were uniformly mixed in N-methylpyrrolidone (NMP) at a mass ratio of 7:2:1 to form a slurry. The total mass of these nanosheets, Ketjen black, and PVDF was 20 mg, and the volume of NMP was 200 μL. The slurry was then evenly coated on a carbon paper surface and dried in a forced-air drying oven at 60°C for 12 hours to obtain a hydrogen-molybdenum bronze electrode sheet. Electrochemical testing was performed in a 9.5 M H₃PO₄ electrolyte. A three-electrode test system was assembled in an electrolytic cell mold, using the hydrogen-molybdenum bronze electrode sheet, activated carbon membrane, and Ag / AgCl electrode as the working, counter, and reference electrodes, respectively.

[0051] Figure 4 The constant current charge and discharge curves of the hydrogen-molybdenum-bronze electrode sheet at different current densities are shown in Figure 2. The hydrogen-molybdenum-bronze electrode is charged and discharged at 2, 5, 10, 15, 20, 30, 50, 70, and 100 A·g -1 The specific mass capacities at current densities of 405, 371, 334, 312, 297, 282, 262, 244, and 227 mAh·g -1 , which shows that the hydrogen-molybdenum-bronze electrode has excellent rate performance.

[0052] Figure 5 The capacity comparison chart of the hydrogen-molybdenum-bronze electrode at different temperatures is shown in Figure 2. The maximum specific mass capacity of the hydrogen-molybdenum-bronze electrode at 0, -20, -40, and -60°C is 368, 349, 325, and 284 mAh g, respectively. -1 , and also has excellent rate capacity, proving the low-temperature applicability of hydrogen-molybdenum-bronze electrodes.

[0053] Figure 6The constant current charge and discharge curves of the hydrogen-molybdenum-bronze electrode sheet at -80°C are shown. The maximum specific mass capacity of the hydrogen-molybdenum-bronze electrode at ultra-low temperature of -80°C is 194 mAh g -1 .

[0054] Example 2

[0055] A method for preparing a hydrogen-molybdenum bronze nanosheet material comprises the following steps:

[0056] Step 1, prepare MoO3 suspension:

[0057] 5 g of MoO3 particles with a particle size of less than 10 μm were weighed and added to 100 mL of deionized water. The mixture was rapidly stirred at 500 rpm under magnetic stirring for 1 h to obtain a uniform MoO3 suspension.

[0058] Step 2, prepare Na2S2O4 solution:

[0059] Weigh 2 g of Na2S2O4 powder, dissolve it in 100 mL of deionized water, and stir rapidly at 500 rpm under magnetic stirring for 30 min to obtain a uniform Na2S2O4 solution.

[0060] Step 3, mixed solution reaction:

[0061] The Na2S2O4 solution was slowly added to the MoO3 suspension and rapidly stirred at 500 rpm for 6 h at room temperature. After the reaction was completed, the product was filtered, washed and dried.

[0062] Step 4, product post-processing:

[0063] 750 mg of the above product was added to 100 mL of 1 M HCl aqueous solution, and the mixture was rapidly stirred at room temperature for 6 hours. The mixture was filtered, washed, and dried to obtain hydrogen molybdenum bronze nanosheet material.

[0064] Example 3

[0065] A method for preparing a hydrogen-molybdenum bronze nanosheet material comprises the following steps:

[0066] Step 1, prepare MoO3 suspension:

[0067] 5 g of MoO3 particles with a particle size of less than 10 μm were weighed and added to 100 mL of deionized water. The mixture was rapidly stirred at 500 rpm under magnetic stirring for 3 h to obtain a uniform MoO3 suspension.

[0068] Step 2, prepare Na2S2O4 solution:

[0069] Weigh 2 g of Na2S2O4 powder, dissolve it in 100 mL of deionized water, and stir rapidly under magnetic stirring for 30 min to obtain a uniform Na2S2O4 solution.

[0070] Step 3, mixed solution reaction:

[0071] The Na2S2O4 solution was slowly added to the MoO3 suspension and rapidly stirred at 500 rpm for 6 h at room temperature. After the reaction was completed, the product was filtered, washed and dried.

[0072] Step 4, product post-processing:

[0073] 750 mg of the above product was added to 100 mL of 1 M HCl aqueous solution, and the mixture was rapidly stirred at 500 rpm at room temperature for 6 hours. The mixture was filtered, washed, and dried to obtain hydrogen molybdenum bronze nanosheet material.

[0074] Example 4

[0075] A method for preparing a hydrogen-molybdenum bronze nanosheet material comprises the following steps:

[0076] Step 1, prepare MoO3 suspension:

[0077] 5 g of MoO3 particles with a particle size of less than 10 μm were weighed and added to 100 mL of deionized water. The mixture was rapidly stirred at 500 rpm under magnetic stirring for 8 h to obtain a uniform MoO3 suspension.

[0078] Step 2, prepare Na2S2O4 solution:

[0079] Weigh 2 g of Na2S2O4 powder, dissolve it in 100 mL of deionized water, and stir rapidly under magnetic stirring for 30 min to obtain a uniform Na2S2O4 solution.

[0080] Step 3, mixed solution reaction:

[0081] The Na2S2O4 solution was slowly added to the MoO3 suspension and rapidly stirred at 500 rpm for 6 h at room temperature. After the reaction was completed, the product was filtered, washed and dried.

[0082] Step 4, product post-processing:

[0083] 750 mg of the above product was added to 100 mL of 1 M HCl aqueous solution, and the mixture was rapidly stirred at 500 rpm at room temperature for 6 hours. The mixture was filtered, washed, and dried to obtain hydrogen molybdenum bronze nanosheet material.

[0084] Example 5

[0085] A method for preparing a hydrogen-molybdenum bronze nanosheet material comprises the following steps:

[0086] Step 1, prepare MoO3 suspension:

[0087] 5 g of MoO3 particles with a particle size of less than 10 μm were weighed and added to 100 mL of deionized water. The mixture was rapidly stirred at 500 rpm for 30 min under magnetic stirring to obtain a uniform MoO3 suspension.

[0088] Step 2, prepare Na2S2O4 solution:

[0089] Weigh 2 g of Na2S2O4 powder, dissolve it in 100 mL of deionized water, and stir rapidly under magnetic stirring for 30 min to obtain a uniform Na2S2O4 solution.

[0090] Step 3, mixed solution reaction:

[0091] The Na2S2O4 solution was slowly added to the MoO3 suspension and rapidly stirred at 500 rpm for 6 h at room temperature. After the reaction was completed, the product was filtered, washed and dried.

[0092] Step 4, product post-processing:

[0093] 750 mg of the above product was added to 50 mL of 1 M HCl aqueous solution, and the mixture was rapidly stirred at 500 rpm at room temperature for 6 hours. The mixture was filtered, washed, and dried to obtain hydrogen molybdenum bronze nanosheet material.

[0094] Example 6

[0095] A method for preparing a hydrogen-molybdenum bronze nanosheet material comprises the following steps:

[0096] Step 1, prepare MoO3 suspension:

[0097] 5 g of MoO3 particles with a particle size of less than 10 μm were weighed and added to 100 mL of deionized water. The mixture was rapidly stirred at 500 rpm for 30 min under magnetic stirring to obtain a uniform MoO3 suspension.

[0098] Step 2, prepare Na2S2O4 solution:

[0099] Weigh 2 g of Na2S2O4 powder, dissolve it in 100 mL of deionized water, and stir rapidly under magnetic stirring for 30 min to obtain a uniform Na2S2O4 solution.

[0100] Step 3, mixed solution reaction:

[0101] The Na2S2O4 solution was slowly added to the MoO3 suspension and rapidly stirred at 500 rpm for 6 h at room temperature. After the reaction was completed, the product was filtered, washed and dried.

[0102] Step 4, product post-processing:

[0103] 750 mg of the above product was added to 200 mL of 1 M HCl aqueous solution, and rapidly stirred at 500 rpm at room temperature for 6 hours. The product was filtered, washed, and dried to obtain hydrogen molybdenum bronze nanosheet material.

[0104] Comparative Example 1

[0105] The material of Comparative Example 1 is precursor MoO3 particles, and the electrode sheet preparation process is the same as that of Example 1.

[0106] The test results of Examples 1 to 6 and Comparative Example 1 at different current densities are shown in Table 1.

[0107] Table 1 Performance data of electrode materials prepared under different formulations

[0108]

[0109] As can be seen from Table 1, the hydrogen-molybdenum-bronze electrode material in Example 1 has excellent specific capacity and rate performance.

[0110] The above embodiments are merely specific implementations of the present invention. Persons skilled in the art may make various modifications and improvements within the technical scope of the present invention, all of which are encompassed within the scope of protection of the present invention. The scope of protection of the present invention shall be determined by the claims.

Claims

1. A method for preparing hydrogen molybdenum bronze nanosheet material, characterized in that: MoO3 particles were added to deionized water and stirred continuously to form a MoO3 slurry; Na2S2O4 was dissolved in deionized water to prepare a Na2S2O4 solution; the Na2S2O4 solution was added to the MoO3 slurry under rapid stirring to initiate a reaction, wherein the molar ratio of MoO3 to Na2S2O4 was 3:1, and the color of the reaction slurry changed from white to purple. After continuous rapid stirring for 1 to 8 hours, the solid powder was collected and placed in a 1 M HCl aqueous solution and stirred rapidly for 6 hours, and then filtered, washed, and dried to obtain hydrogen molybdenum bronze nanosheet material.

2. The method for preparing a hydrogen molybdenum bronze nanosheet material according to claim 1, wherein: The MoO3 particles are orthorhombic molybdenum trioxide particles, and the particle size is less than 10 μm.

3. The hydrogen molybdenum bronze nanosheet material prepared by the preparation method according to any one of claims 1 to 2, characterized in that: The nanosheet material contains crystal water in its structure.

4. The hydrogen molybdenum bronze nanosheet material according to claim 3, characterized in that: The thickness of the nanosheet is 10 nm to 50 nm, and the length is 1 μm to 5 μm.

5. Use of the hydrogen-molybdenum-bronze nanosheet material according to claim 3 as an electrode in a proton hybrid capacitor.

6. A hydrogen-molybdenum bronze electrode sheet, characterized in that: Contains the hydrogen molybdenum bronze nanosheet material according to claim 6.

7. The hydrogen-molybdenum-bronze electrode sheet according to claim 6, characterized in that: The preparation method of the hydrogen-molybdenum-bronze material electrode sheet is as follows: hydrogen-molybdenum-bronze nanosheets are used as active materials, mixed evenly with Ketjen black and polyvinylidene fluoride to obtain a mixture, then N-methylpyrrolidone is added dropwise to the mixture to form a slurry, and then the slurry is evenly coated on the surface of carbon paper, and dried to obtain the hydrogen-molybdenum-bronze material electrode sheet.

8. The hydrogen-molybdenum-bronze electrode sheet according to claim 6, characterized in that: The operating temperature of the hydrogen-molybdenum-bronze nanosheet electrode is -80~25°C.

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