Preparation method of p-c@mno2 nanoflower battery positive electrode material and application of p-c@mno2 nanoflower battery positive electrode material in aqueous zinc ion battery

Abstract

The application belongs to the technical field of materials, and discloses a preparation method of P-C@MnO2 nanoflower battery positive electrode material and application of the material in water-based zinc ion batteries. The electrode material P-C@MnO2 is successfully prepared by a simple calcination method and a hydrothermal method. It can be concluded from electrochemical tests that the P-C@MnO2 electrode material has higher specific capacity and better cycle stability than the pure MnO2 electrode material. The introduction of phosphorus and carbon in the synthesis process increases the active sites, effectively promotes the ion diffusion and charge transfer, improves the conductivity of MnO2, reduces the internal resistance, and maintains the structural flexibility and stability of the material, so as to improve the overall performance of the water-based zinc ion battery.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of materials, and particularly relates to a preparation method of P-C@MnO2 nanoflower battery positive electrode material and application thereof in aqueous zinc ion batteries. BACKGROUND

[0002] With the increasing concern about environmental problems and the high demand for sustainable energy, it is urgent to develop new materials for high-performance energy storage and conversion. The global demand for renewable energy and environmental protection technology is growing, and energy storage technology, especially high-efficiency and environmentally friendly battery technology, has become a research hotspot. In the past few decades, lithium ion batteries have been widely selected as backup batteries in the energy field from electric vehicles to household appliances. However, due to the limited resources, rising prices and high risk of lithium, the further development of lithium ion batteries is hindered. Under the background of resource constraints and environmental pressure of traditional battery technologies such as lithium ion batteries, aqueous zinc ion batteries stand out with their unique advantages.

[0003] Aqueous zinc ion batteries, unlike traditional lithium ion batteries, use neutral or weakly acidic zinc salt aqueous solution as electrolyte (pH: 3.6-6.0), have low production cost, are safe and environmentally friendly, and have good development prospects in large-scale energy storage field, and are considered by researchers as a more promising battery research direction. The electrochemical performance of zinc ion battery is highly dependent on its positive electrode material. In recent years, the development of positive electrode materials mainly focuses on manganese-based materials, vanadium-based materials and prussian blue and its analogues. Among them, manganese-based materials are considered to be the most promising positive electrode material due to their different crystal structures and three-dimensional spatial framework. However, the unnecessary phase change, inevitable dissolution and undesirable reversible capacity of manganese-based materials hinder its further development. The technology introduces phosphorus and carbon, increases the active site, effectively promotes the diffusion and charge transfer of ions, improves the conductivity of MnO2, reduces its internal resistance, and maintains the structural flexibility and stability of the material, thereby improving the overall performance of the aqueous zinc ion battery. SUMMARY

[0004] To solve the above problems, the application provides a preparation method of P-C@MnO2 nanoflower battery positive electrode material and application thereof in aqueous zinc ion batteries.

[0005] The technical scheme adopted by the application is:

[0006] A P-C@MnO2 nanoflower battery positive electrode material, and a preparation method thereof includes the following steps:

[0007] 1) quickly mix glucose and P2O5 in a 50 mL reaction kettle for 5 min, then transfer to a stainless steel autoclave, and then heat to obtain a black expanded precursor;

[0008] 2) calcine the black expanded precursor in a tube furnace, then wash the obtained product to remove impurities, dry after filtration to obtain P-C powder;

[0009] 3) mix potassium permanganate and P-C powder uniformly, stir for 1 h, and dissolve in deionized water for 10 min, then hydrothermally react the fully mixed solution, cool to room temperature, centrifugal wash, and vacuum dry to obtain P-C@MnO2 electrode material.

[0010] Further, in the above method for preparing the P-C@MnO2 nanoflower battery positive electrode material, in step 1), the heating condition is 200℃ for 6h.

[0011] Further, in the above method for preparing the P-C@MnO2 nanoflower battery positive electrode material, in step 2), the calcination condition is first heated to 450℃ for 3h, and then heated to 800℃ for 3h under argon atmosphere, with a heating gradient of 5℃ / min -1 .

[0012] Further, in the above method for preparing the P-C@MnO2 nanoflower battery positive electrode material, in step 3), the mass ratio of potassium permanganate to P-C is 0.63:0.05-0.15.

[0013] Further, in the above method for preparing the P-C@MnO2 nanoflower battery positive electrode material, in step 3), the hydrothermal reaction condition is 180℃ for 6h.

[0014] The P-C@MnO2 nanoflower battery positive electrode material of any one of the above methods for use in aqueous zinc ion batteries.

[0015] Further, the above application, the method comprises the following steps:

[0016] 1) Preparation of positive electrode: mix P-C@MnO2 electrode material, binder and conductive material uniformly, add a small amount of NMP as solvent, mix uniformly, then directly apply on the substrate carbon paper, dry in a vacuum drying oven, and take out to obtain a positive electrode sheet coated with P-C@MnO2 electrode material;

[0017] 2) Preparation of negative electrode: polish the zinc sheet with sandpaper to remove the surface oxide layer, and cut the polished zinc sheet into small round pieces with a diameter of 12mm;

[0018] 3) The positive electrode sheet coated with P-C@MnO2 electrode material prepared in step 1) is used as the positive electrode, the zinc sheet prepared in step 2) is used as the negative electrode, and 1M ZnSO4+0.1M MnSO4 is used as the electrolyte to obtain a water-based zinc ion battery.

[0019] Further, in the application method, the binder in step 1) is PVDF.

[0020] Further, in the application method, the conductive material in step 1) is Super-p.

[0021] Further, in the application method, the thickness of the zinc sheet in step 2) is 0.1mm-0.2mm, and the purity is 99%-99.99%.

[0022] The application has the following beneficial effects:

[0023] 1. By introducing phosphorus and carbon in the synthesis process, the application effectively promotes the diffusion of ions and charge transfer, improves the conductivity of MnO2, reduces the internal resistance, and maintains the structural flexibility and stability of the material.

[0024] 2. The introduction of phosphorus and carbon improves the specific capacity and cycle performance of the material during charging and discharging.

[0025] 3. The electrode material has the characteristics of low cost, environmental friendliness, and high safety.

[0026] 4. The electrode material has the advantages of high energy density and power density.

[0027] 5. The synthesis process and assembly process of the application are simple, easy to operate and control, and suitable for continuous large-scale production.

[0028] 6. The method is also applicable to other metal oxide positive electrode materials and has good universality. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is the SEM diagram of MnO2 and P-C@MnO2 prepared in Example 1.

[0030] Figure 2 is the GCD spectrum of MnO2 and P-C@MnO2 prepared in Example 1.

[0031] Figure 3 is the XRD diagram of MnO2 and P-C@MnO2 prepared in Example 1.

[0032] Figure 4 is the specific capacity diagram of MnO2 and P-C@MnO2 prepared in Example 1. DETAILED DESCRIPTION

[0033] The technical solutions of the present application are further described below, but are not limited thereto. Any modification or equivalent replacement of the technical solutions of the present application without departing from the spirit and scope of the technical solutions of the present application shall be covered in the protection scope of the present application.

[0034] Example 1

[0035] (I) Preparation of P-C@MnO2 electrode material

[0036] First, 1 g of glucose and 5 g of P2O5 were quickly mixed in a 50 mL reaction kettle for 5 min, and then transferred to a stainless steel autoclave, followed by heating to 200℃ for 6 h to obtain a black expanded precursor. Second, the black expanded precursor was placed in a tube furnace and heated to 450℃ under argon atmosphere for 3 h, and then heated to 800℃ for 3 h, with a heating gradient of 5℃ min -1 Then, the obtained product was rinsed three times in deionized water and CS2 to remove impurities, filtered and vacuum dried at 80℃ to obtain P-C powder. Finally, 0.63 g of potassium permanganate and 0.1 g of P-C powder were dissolved in 40 mL of deionized water, stirred for 1 h, ultrasonicated for 10 min, and then subjected to hydrothermal reaction at 180℃ for 6 h. When the reaction kettle was completely cooled to room temperature, the product was taken out, washed three times with deionized water and anhydrous ethanol by centrifugation, and vacuum dried for 24 h to obtain the P-C@MnO2 electrode material.

[0037] (II) Preparation of MnO2 electrode material

[0038] Directly, 0.63 g of potassium permanganate was dissolved in 40 mL of deionized water, stirred for 1 h, ultrasonicated for 10 min, and then subjected to hydrothermal reaction at 180℃ for 6 h. When the reaction kettle was completely cooled to room temperature, the product was taken out, washed three times with deionized water and anhydrous ethanol by centrifugation, and vacuum dried for 24 h to obtain the MnO2 electrode material. The preparation method of MnO2 is similar to that of P-C@MnO2, and the proportion of the materials is not changed. The difference is that no P-C powder is added.

[0039] (III) Detection

[0040] Figure 1 is the SEM spectrum of MnO2 and P-C@MnO2 prepared in this example. As can be seen from Figure 1 the prepared material is uniform nanoflower. Figure 2 is the GCD spectrum of MnO2 and P-C@MnO2. As can be seen from Figure 2 the performance of the electrode material after doping is significantly improved. Figure 3 is the XRD spectrum of MnO2 and P-C@MnO2. As can be seen fromFigure 3 It can be seen that the XRD spectrum of the sample exhibits its characteristic peaks, indicating that it is successfully compounded. Figure 4 is the specific capacity graph of MnO2 and P-C@MnO2. From the figure, it can be seen that the specific capacity of P-C@MnO2 is much greater than that of pure MnO2. Figure 4 It can be seen that the specific capacity of P-C@MnO2 is much greater than that of pure MnO2.

[0041] Example 2 Preparation of P-C@MnO2 electrode material

[0042] First, 1g of glucose and 5g of P2O5 were quickly mixed in a 50mL reaction kettle for 5min, then transferred to a stainless steel autoclave, and then heated to 200℃ for 6h to obtain a black expanded precursor. Second, the black expanded precursor was placed in a tube furnace and heated to 450℃ under an argon atmosphere for 3h, and then heated to 800℃ for 3h, with a heating gradient of 5℃ min -1 Then, the obtained product was rinsed three times in deionized water and CS2 to remove impurities, filtered and vacuum dried at 80℃ to obtain P-C powder. Finally, 0.63g of potassium permanganate and 0.05g of P-C powder were dissolved in 40mL of deionized water, stirred for 1h, and then ultrasonicated for 10min, followed by a hydrothermal reaction at 180℃ for 6h. When the reaction kettle was completely cooled to room temperature, the product was removed, washed three times with deionized water and anhydrous ethanol by centrifugation, and vacuum dried for 24h to obtain the P-C@MnO2 electrode material.

[0043] Example 3 Preparation of P-C@MnO2 electrode material

[0044] First, 1g of glucose and 5g of P2O5 were quickly mixed in a 50mL reaction kettle for 5min, then transferred to a stainless steel autoclave, and then heated to 200℃ for 6h to obtain a black expanded precursor. Second, the black expanded precursor was placed in a tube furnace and heated to 450℃ under an argon atmosphere for 3h, and then heated to 800℃ for 3h, with a heating gradient of 5℃ min -1 Then, the obtained product was rinsed three times in deionized water and CS2 to remove impurities, filtered and vacuum dried at 80℃ to obtain P-C powder. Finally, 0.63g of potassium permanganate and 0.05g of P-C powder were dissolved in 40mL of deionized water, stirred for 1h, and then ultrasonicated for 10min, followed by a hydrothermal reaction at 180℃ for 6h. When the reaction kettle was completely cooled to room temperature, the product was removed, washed three times with deionized water and anhydrous ethanol by centrifugation, and vacuum dried for 24h to obtain the P-C@MnO2 electrode material.

[0045] Example 4 Preparation of negative electrode material

[0046] The zinc sheet with a thickness of 0.1 mm and a purity of 99.99% was repeatedly polished with sandpaper to remove the surface oxide layer, and the polished zinc sheet was cut into small round pieces with a diameter of 12 mm for standby.

[0047] Preparation of negative electrode material

[0048] The zinc sheet with a thickness of 0.2 mm and a purity of 99.99% was repeatedly polished with sandpaper to remove the surface oxide layer, and the polished zinc sheet was cut into small round pieces with a diameter of 12 mm for standby.

[0049] Preparation of aqueous zinc ion battery

[0050] 1) Preparation of positive electrode: the P-C@MnO2 electrode material prepared in Example 1 and the MnO2 electrode material prepared in Example 1 were mixed with PVDF and Super-p respectively, and a small amount of NMP was added as a solvent. After mixing, the mixture was directly coated on the substrate carbon paper, and then dried in a vacuum drying oven. The positive electrode sheet coated with P-C@MnO2 electrode material and MnO2 electrode material respectively was obtained.

[0051] 2) The positive electrode sheet prepared in step 1) was used as the positive electrode, the negative electrode material prepared in Example 4 was used as the negative electrode, and the electrolyte was selected as 1M ZnSO4+0.1M MnSO4. An aqueous zinc ion battery was obtained and subjected to electrochemical test.

[0052] Preparation of aqueous zinc ion battery

[0053] 1) Preparation of positive electrode: the P-C@MnO2 electrode material prepared in Example 2 and the MnO2 electrode material prepared in Example 1 were mixed with PVDF and Super-p respectively, and a small amount of NMP was added as a solvent. After mixing, the mixture was directly coated on the substrate carbon paper, and then dried in a vacuum drying oven. The positive electrode sheet coated with P-C@MnO2 electrode material and MnO2 electrode material respectively was obtained.

[0054] 2) The positive electrode sheet prepared in step 1) was used as the positive electrode, the negative electrode material prepared in Example 4 was used as the negative electrode, and the electrolyte was selected as 1M ZnSO4+0.1M MnSO4. An aqueous zinc ion battery was obtained and subjected to electrochemical test.

[0055] Preparation of aqueous zinc ion battery

[0056] 1) Preparation of positive electrode: the P-C@MnO2 electrode material prepared in Example 3 and the MnO2 electrode material prepared in Example 1 were mixed with PVDF and Super-p respectively, and a small amount of NMP was added as a solvent. After mixing, the mixture was directly coated on the substrate carbon paper, and then dried in a vacuum drying oven. The positive electrode sheet coated with P-C@MnO2 electrode material and MnO2 electrode material respectively was obtained.

[0057] 2) The positive electrode prepared in step 1) is used as the positive electrode, the negative electrode material prepared in Example 4 is used as the negative electrode, and the electrolyte is selected as 1M ZnSO4+0.1M MnSO4, to obtain a water-based zinc ion battery and perform electrochemical test.

[0058] Preparation of a water-based zinc ion battery

[0059] 1) Preparation of the positive electrode: the P-C@MnO2 electrode material prepared in Example 1 and the MnO2 electrode material prepared in Example 1 are mixed with PVDF and Super-p respectively, and a small amount of NMP is added as a solvent, and then the mixture is evenly coated on the substrate carbon paper, and then dried in a vacuum drying oven, and then taken out to obtain the positive electrode sheet coated with the P-C@MnO2 electrode material and the MnO2 electrode material respectively;

[0060] 2) The positive electrode prepared in step 1) is used as the positive electrode, the negative electrode material prepared in Example 5 is used as the negative electrode, and the electrolyte is selected as 1M ZnSO4+0.1M MnSO4, to obtain a water-based zinc ion battery and perform electrochemical test.

[0061] Preparation of a water-based zinc ion battery

[0062] 1) Preparation of the positive electrode: the P-C@MnO2 electrode material prepared in Example 2 and the MnO2 electrode material prepared in Example 1 are mixed with PVDF and Super-p respectively, and a small amount of NMP is added as a solvent, and then the mixture is evenly coated on the substrate carbon paper, and then dried in a vacuum drying oven, and then taken out to obtain the positive electrode sheet coated with the P-C@MnO2 electrode material and the MnO2 electrode material respectively;

[0063] 2) The positive electrode prepared in step 1) is used as the positive electrode, the negative electrode material prepared in Example 5 is used as the negative electrode, and the electrolyte is selected as 1M ZnSO4+0.1M MnSO4, to obtain a water-based zinc ion battery and perform electrochemical test.

[0064] Preparation of a water-based zinc ion battery

[0065] 1) Preparation of the positive electrode: the P-C@MnO2 electrode material prepared in Example 3 and the MnO2 electrode material prepared in Example 1 are mixed with PVDF and Super-p respectively, and a small amount of NMP is added as a solvent, and then the mixture is evenly coated on the substrate carbon paper, and then dried in a vacuum drying oven, and then taken out to obtain the positive electrode sheet coated with the P-C@MnO2 electrode material and the MnO2 electrode material respectively;

[0066] 2) The positive electrode sheet prepared in step 1) was used as the positive electrode, the negative electrode material prepared in Example 5 was used as the negative electrode, and the electrolyte was selected as 1M ZnSO4+0.1M MnSO4, to obtain a water-based zinc ion battery and perform electrochemical testing.

[0067] The six water-based zinc ion batteries assembled according to the above Examples 6-11 show that the electrochemical performance of Example 6 is the best, and the specific capacity is improved at each current density (as shown in Figure 4 The positive electrode material in Example 1 is used in Example 6, wherein 0.1 g of P-C powder is added, indicating that the proportion is the most appropriate at this time, providing more active sites, thus more easily storing more zinc ions, and at the same time promoting the embedding and extraction of zinc ions, thereby improving the electrochemical performance.

Claims

1. A P-C@MnO2 nanoflower battery cathode material, characterized in that, The preparation method comprises the following steps: 1) rapidly mixing glucose and P2O5 in a 50 mL reaction kettle for 5 min, then transferring into a stainless steel autoclave, and then heating to obtain a black expanded precursor; 2) calcining the black expanded precursor in a tube furnace, then washing the obtained product to remove impurities, drying after filtration to obtain P-C powder; 3) uniformly mixing potassium permanganate and P-C powder, stirring for 1 h, ultrasonicating for 10 min in deionized water, and hydrothermally reacting the well-mixed solution, cooling to room temperature, centrifugal washing, and vacuum drying to obtain a P-C@MnO2 electrode material.

2. The P-C@MnO2 nanoflower battery cathode material of claim 1, characterized in that, In step 1), the heating condition is 200℃ for 6 h.

3. The P-C@Mn02 nanoflower battery cathode material of claim 1, characterized in that, In step 2), the calcination conditions are heating to 450°C for 3h, then to 800°C for 3h under argon atmosphere, with a heating gradient of 5°C min -1 .

4. The P-C@Mn02 nanoflower battery cathode material of claim 1, characterized in that, In step 3), the mass ratio of potassium permanganate to P-C is 0.63:0.05-0.

15.

5. The P-C@Mn02 nanoflower battery cathode material of claim 1, characterized in that, In step 3), the hydrothermal reaction condition is 180℃ for 6 h.

6. Application of the P-C@MnO2 nanoflower battery positive electrode material in the water-based zinc ion battery according to any one of claims 1-5.

7. Use according to claim 6, characterized in that, The method comprises the following steps: 1) preparation of the positive electrode: uniformly mixing the P-C@MnO2 electrode material, a binder and a conductive material, adding a small amount of NMP as a solvent, uniformly mixing, directly coating on a carbon paper substrate, drying in a vacuum drying oven, and taking out to obtain a positive electrode sheet coated with the P-C@MnO2 electrode material; 2) preparation of the negative electrode: polishing the zinc sheet with sandpaper to remove the surface oxide layer, cutting the polished zinc sheet into small round sheets with a diameter of 12 mm; 3) taking the positive electrode sheet coated with the P-C@MnO2 electrode material prepared in step 1) as the positive electrode, taking the zinc sheet prepared in step 2) as the negative electrode, and taking 1M ZnSO4+0.1M MnSO4 as the electrolyte to obtain a water-based zinc ion battery.

8. Use according to claim 7, characterized in that, In step 1), the binder is PVDF.

9. Use according to claim 7, characterized in that, In step 1), the conductive material is Super-p.

10. Use according to claim 7, characterized in that, In step 2), the thickness of the zinc sheet is 0.1-0.2 mm, and the purity is 99%-99.99%.

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