Preparation method of AgVO3@Ag2Cu(VO3)4 composite electrode material and its application in aqueous zinc ion batteries

Abstract

This invention belongs to the field of materials technology, specifically to a method for preparing an AgVO3@Ag2Cu(VO3)4 composite electrode material and its application in aqueous zinc-ion batteries. The present invention prepares the AgVO3@Ag2Cu(VO3)4 electrode material through a simple one-step hydrothermal method. The expanded interlayer spacing effectively promotes ion diffusion and charge transfer, improving the conductivity of the AgVO3@Ag2Cu(VO3)4, reducing its internal resistance, while maintaining the structural flexibility and stability of the material, thereby enhancing the overall performance of aqueous zinc-ion batteries.

Description

Technical Field

[0001] The present invention belongs to the field of material technology, and specifically relates to a preparation method of an AgVO3@Ag2Cu(VO3)4 composite electrode material and its application in aqueous zinc ion batteries. Background Art

[0002] The development of energy storage devices is an important approach to addressing the energy crisis and utilizing efficient renewable energy. Among them, lithium-ion batteries (LIBs) are widely recognized for their high energy density and long cycle life, and large-scale production has been achieved. However, due to the limited and uneven distribution of global lithium resources, the price of lithium is on an upward trend. In addition, the use of chemically active lithium and flammable organic electrolytes poses safety risks, which greatly limits the widespread application of lithium batteries in portable energy storage devices. Especially today, as people's living standards continue to improve, smart wearable electronic products with health monitoring functions are developing rapidly, and portable batteries with high safety, low cost, and high energy density are increasingly attracting people's attention. Therefore, research and development of new energy storage battery systems that can replace lithium-ion batteries and combine low cost, high energy, high safety, and environmental protection are important directions for sustainable development.

[0003] As one of the emerging candidate materials, aqueous rechargeable zinc-ion batteries (ZIBs) have attracted great attention due to their inherent safety, lack of flame or explosion risk, abundance of all device components, and ease of battery fabrication. From an electrochemical point of view, the zinc anode has a low redox potential (0.76 V compared to the standard hydrogen electrode), and the Zn 2+ The double electron transfer of Zn is more likely to occur than that of monovalent alkali ions (such as Li + , K + Or Na + ) offer higher energy density. Consequently, ZIBs have garnered significant attention and have made significant progress in recent years. However, currently used electrode materials, such as manganese oxides and Prussian blue compounds, suffer from problems such as unwanted phase transitions, unavoidable dissolution, and suboptimal reversibility, leading to poor conductivity, poor rate capability, and limited cycling performance, making them difficult to meet the growing demand. Summary of the Invention

[0004] To solve the above problems, the present invention provides a method for preparing an AgVO3@Ag2Cu(VO3)4 composite electrode material and its application in aqueous zinc ion batteries.

[0005] The technical solution adopted in the present invention is:

[0006] An AgVO3@Ag2Cu(VO3)4 composite electrode material, the preparation method of which comprises the following steps:

[0007] First, copper nitrate and silver nitrate are weighed and dissolved in deionized water to form solution A; then, ammonium vanadate is weighed and dissolved in deionized water to form solution B; solution B is then dropped into solution A and stirred at room temperature to fully mix, and the fully mixed solution is transferred to a stainless steel hydrothermal reactor lined with polytetrafluoroethylene for hydrothermal reaction, cooled to room temperature, centrifuged to remove residual reactants, and vacuum dried to obtain an AgVO3@Ag2Cu(VO3)4 composite electrode material.

[0008] Preferably, in the above-mentioned method for preparing the AgVO3@Ag2Cu(VO3)4 composite electrode material, the molar ratio of copper nitrate:silver nitrate:ammonium vanadate is 0.2-0.3:0.5:1.0.

[0009] Preferably, in the above-mentioned method for preparing the AgVO3@Ag2Cu(VO3)4 composite electrode material, the copper nitrate is Cu(NO3)2·3H2O.

[0010] Preferably, in the above-mentioned method for preparing the AgVO3@Ag2Cu(VO3)4 composite electrode material, ammonium vanadate is dissolved in deionized water at 100°C.

[0011] Preferably, in the above-mentioned method for preparing the AgVO3@Ag2Cu(VO3)4 composite electrode material, the hydrothermal reaction conditions are reaction at 235°C for 72 hours.

[0012] Application of any of the above-mentioned AgVO3@Ag2Cu(VO3)4 composite electrode materials in aqueous zinc-ion batteries.

[0013] Furthermore, the above application method includes the following steps:

[0014] 1) Preparation of the positive electrode: After uniformly mixing the AgVO3@Ag2Cu(VO3)4 composite material with the binder and the conductive material, a small amount of NMP was added as a solvent. After uniform mixing, the mixture was directly applied on the substrate carbon paper, dried in a vacuum drying oven, and taken out to obtain a positive electrode sheet coated with the AgVO3@Ag2Cu(VO3)4 composite material;

[0015] 2) Preparation of the negative electrode: The zinc sheet was sanded to remove the surface oxide layer, and the polished zinc sheet was cut into a circular negative electrode sheet with a diameter of 12 mm;

[0016] 3) Using the positive electrode sheet prepared in step 1) as the positive electrode, the negative electrode sheet prepared in step 2) as the negative electrode, and 3M zinc trifluoromethanesulfonate as the electrolyte to obtain an aqueous zinc ion battery.

[0017] Furthermore, in the above application, in step 1), the binder is PVDF.

[0018] Furthermore, in the above application, in step 1), the conductive material is Super-p.

[0019] Furthermore, in the above application, in step 2), the zinc sheet has a thickness of 0.1 mm to 0.3 mm and a purity of 99% to 99.99%.

[0020] The beneficial effects of the present invention are:

[0021] 1. Through the one-step synthesis of AgVO3@Ag2Cu(VO3)4 composite electrode material, the conductivity and ion diffusion rate of the material are significantly improved, and the internal resistance is reduced.

[0022] 2. The interlayer spacing increases, thereby improving the specific capacity and rate performance of the material during the charge and discharge process.

[0023] 3. It has the characteristics of low cost, environmental friendliness and high safety.

[0024] 4. It has the advantages of higher energy density and power density.

[0025] 5. The synthesis process and assembly process are simple, easy to operate and control, and suitable for continuous large-scale production.

[0026] 6. After modification, the stability of the electrode material is improved and the capacity is increased from the previous 115mAh / g to 136mAh / g.

[0027] 7. The method of the present invention is also applicable to other metal oxide positive electrode materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is the XRD spectrum of the AgVO3@Ag2Cu(VO3)4 composite electrode material prepared in Example 1.

[0029] Figure 2 This is the SEM spectrum of the AgVO3@Ag2Cu(VO3)4 composite electrode material prepared in Example 1.

[0030] Figure 3 This is a diagram of the specific capacity of the AgVO3@Ag2Cu(VO3)4 composite electrode material prepared in Example 1.

[0031] Figure 4 This is a cycle diagram of the AgVO3@Ag2Cu(VO3)4 composite electrode material prepared in Example 1. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described below, but is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention that does not depart from the spirit and scope of the technical solution of the present invention should be included in the scope of protection of the present invention.

[0033] Example 1 Preparation of AgVO3@Ag2Cu(VO3)4 Composite Material

[0034] (1) The preparation method of AgVO3@Ag2Cu(VO3)4 composite material is as follows:

[0035] First, 0.06 g of copper nitrate trihydrate and 0.08 g of silver nitrate were weighed and dissolved in 9 mL of deionized water to form solution A. Then, 0.12 g of ammonium vanadate was weighed and dissolved in 7 mL of deionized water at 100°C to form solution B. Solution B was then dropped into solution A and stirred at room temperature to fully mix. The fully mixed solution was transferred to a polytetrafluoroethylene-lined stainless steel hydrothermal reactor and hydrothermally reacted at 235°C for 72 hours. When the reactor was completely cooled to room temperature, the product was taken out, centrifuged and washed three times with deionized water and anhydrous ethanol respectively, and vacuum dried to obtain AgVO3@Ag2Cu(VO3)4.

[0036] (2) Testing

[0037] Figure 1 This is the XRD spectrum of AgVO3@Ag2Cu(VO3)4 prepared in this example. Figure 1 It can be seen that the XRD spectrum of the sample shows the characteristic diffraction peaks of AgVO3 and Ag2Cu(VO3)4 at the same time, indicating that AgVO3@Ag2Cu(VO3)4 was successfully synthesized. Figure 2 This is the SEM spectrum of AgVO3@Ag2Cu(VO3)4. Figure 2 It can be seen that the prepared AgVO3@Ag2Cu(VO3)4 is a typical rod-like structure. Figure 3 This is the specific capacity diagram of AgVO3@Ag2Cu(VO3)4. Figure 4 This is the cycle diagram of AgVO3@Ag2Cu(VO3)4. Figure 3 and 4 It can be seen that the specific capacity and cycle stability of AgVO3@Ag2Cu(VO3)4 are better than those of pure AgVO3.

[0038] Example 2 Preparation of AgVO3@Ag2Cu(VO3)4 Composite Material

[0039] First, 0.05 g of copper nitrate trihydrate and 0.08 g of silver nitrate were weighed and dissolved in 9 mL of deionized water to form solution A. Then, 0.12 g of ammonium vanadate was weighed and dissolved in 7 mL of deionized water at 100°C to form solution B. Solution B was then dropped into solution A and stirred at room temperature to fully mix. The fully mixed solution was transferred to a polytetrafluoroethylene-lined stainless steel hydrothermal reactor and hydrothermally reacted at 235°C for 72 hours. When the reactor was completely cooled to room temperature, the product was taken out, centrifuged and washed three times with deionized water and anhydrous ethanol respectively, and vacuum dried to obtain AgVO3@Ag2Cu(VO3)4.

[0040] Example 3 Preparation of AgVO3@Ag2Cu(VO3)4 Composite Material

[0041] First, 0.07 g of copper nitrate trihydrate and 0.08 g of silver nitrate were weighed and dissolved in 9 mL of deionized water to form solution A. Then, 0.12 g of ammonium vanadate was weighed and dissolved in 7 mL of deionized water at 100°C to form solution B. Solution B was then dropped into solution A and stirred at room temperature to fully mix. The fully mixed solution was transferred to a polytetrafluoroethylene-lined stainless steel hydrothermal reactor and hydrothermally reacted at 235°C for 72 hours. When the reactor was completely cooled to room temperature, the product was taken out, centrifuged and washed three times with deionized water and anhydrous ethanol respectively, and vacuum dried to obtain AgVO3@Ag2Cu(VO3)4.

[0042] Example 4 Preparation of negative electrode material

[0043] A zinc sheet with a thickness of 0.1 mm and a purity of 99.99% was repeatedly polished with sandpaper to remove the oxide layer on the surface. The polished zinc sheet was cut into a circular negative electrode sheet with a diameter of 12 mm for later use.

[0044] Example 5 Preparation of negative electrode materials

[0045] A zinc sheet with a thickness of 0.2 mm and a purity of 99.99% was repeatedly polished with sandpaper to remove the oxide layer on the surface. The polished zinc sheet was cut into a circular negative electrode sheet with a diameter of 12 mm for later use.

[0046] Example 6 Preparation of negative electrode material

[0047] A zinc sheet with a thickness of 0.3 mm and a purity of 99.99% was repeatedly polished with sandpaper to remove the oxide layer on the surface. The polished zinc sheet was cut into a circular negative electrode sheet with a diameter of 12 mm for later use.

[0048] Example 7 Preparation of Aqueous Zinc Ion Battery

[0049] 1) Preparation of the positive electrode: The AgVO3@Ag2Cu(VO3)4 electrode material prepared in Example 1 was mixed evenly with PVDF and Super-p, and a small amount of NMP was added as a solvent. After mixing evenly, the mixture was directly applied to a substrate carbon paper, dried in a vacuum drying oven, and taken out to obtain a positive electrode sheet coated with AgVO3@Ag2Cu(VO3)4;

[0050] 2) The positive electrode sheet prepared in step 1) was used as the positive electrode, the negative electrode sheet prepared in Example 4 was used as the negative electrode, and 3M zinc trifluoromethanesulfonate was selected as the electrolyte to obtain an aqueous zinc ion battery and perform electrochemical testing.

[0051] Example 8 Preparation of Aqueous Zinc Ion Battery

[0052] 1) Preparation of the positive electrode: The AgVO3@Ag2Cu(VO3)4 electrode material prepared in Example 2 was mixed evenly with PVDF and Super-p, and a small amount of NMP was added as a solvent. After mixing evenly, the mixture was directly applied to the substrate carbon paper, dried in a vacuum drying oven, and taken out to obtain a positive electrode sheet coated with AgVO3@Ag2Cu(VO3)4;

[0053] 2) The positive electrode sheet prepared in step 1) was used as the positive electrode, the negative electrode sheet prepared in Example 5 was used as the negative electrode, and 3M zinc trifluoromethanesulfonate was selected as the electrolyte to obtain an aqueous zinc ion battery and perform electrochemical testing.

[0054] Example 9 Preparation of Aqueous Zinc Ion Battery

[0055] 1) Preparation of the positive electrode: The AgVO3@Ag2Cu(VO3)4 electrode material prepared in Example 3 was mixed with PVDF and Super-p, and a small amount of NMP was added as a solvent. After mixing evenly, the mixture was directly applied to the substrate carbon paper, dried in a vacuum drying oven, and taken out to obtain a positive electrode sheet coated with AgVO3@Ag2Cu(VO3)4;

[0056] 2) The positive electrode sheet prepared in step 1) was used as the positive electrode, the negative electrode sheet prepared in Example 6 was used as the negative electrode, and 3M zinc trifluoromethanesulfonate was selected as the electrolyte to obtain an aqueous zinc ion battery and perform electrochemical testing.

[0057] According to the three aqueous zinc ion batteries assembled in Examples 7 to 9, we obtained that Example 7 had the best electrochemical performance, and at a current density of 3A g -1 The long cycle life reaches 1500 cycles and the capacity retention rate is high (such as Figure 4As shown in Figure 7, since the AgVO3@Ag2Cu(VO3)4 nanorods formed when the molar ratio of copper nitrate:silver nitrate:ammonium vanadate is 0.25:0.5:1.0 in Example 7 are more uniform and ordered in size, their interlayer spacing is enlarged to provide more active sites, making it easier to store more zinc ions. At the same time, it promotes the embedding and de-embedding of zinc ions, thereby improving its electrochemical performance.

Claims

1. Application of an AgVO3@Ag2Cu(VO3)4 composite electrode material in an aqueous zinc ion battery, characterized in that: The preparation method of the AgVO3@Ag2Cu(VO3)4 composite electrode material comprises the following steps: First, copper nitrate and silver nitrate are weighed and dissolved in deionized water to form solution A; then, ammonium vanadate is weighed and dissolved in deionized water to form solution B; solution B is then dropped into solution A and stirred at room temperature to fully mix, and the fully mixed solution is transferred to a stainless steel hydrothermal reactor lined with polytetrafluoroethylene for hydrothermal reaction, cooled to room temperature, centrifuged to remove residual reactants, and vacuum dried to obtain an AgVO3@Ag2Cu(VO3)4 composite electrode material.

2. The use according to claim 1, characterized in that In molar ratio, copper nitrate:silver nitrate:ammonium vanadate = 0.2-0.3:0.5:1.

0.

3. The use according to claim 1, characterized in that The copper nitrate is Cu(NO3)2·3H2O.

4. The use according to claim 1, characterized in that Ammonium vanadate was dissolved in deionized water at 100 °C.

5. The use according to claim 1, characterized in that The hydrothermal reaction conditions are: reaction at 235° C. for 72 hours.

6. The use according to claim 1, characterized in that The method comprises the following steps: 1) Preparation of the positive electrode: After uniformly mixing the AgVO3@Ag2Cu(VO3)4 composite material with the binder and the conductive material, a small amount of NMP was added as a solvent. After uniform mixing, the mixture was directly applied on the substrate carbon paper, dried in a vacuum drying oven, and taken out to obtain a positive electrode sheet coated with the AgVO3@Ag2Cu(VO3)4 composite material; 2) Preparation of the negative electrode: Grind the zinc sheet with sandpaper to remove the surface oxide layer, and cut the polished zinc sheet into a circular negative electrode sheet with a diameter of 12 mm; 3) Using the positive electrode sheet prepared in step 1) as the positive electrode, the negative electrode sheet prepared in step 2) as the negative electrode, and 3M zinc trifluoromethanesulfonate as the electrolyte, an aqueous zinc ion battery is obtained.

7. The use according to claim 6, characterized in that In step 1), the binder is PVDF.

8. The use according to claim 6, characterized in that In step 1), the conductive material is Super-p.

9. The use according to claim 6, characterized in that In step 2), the zinc sheet has a thickness of 0.1 mm to 0.3 mm and a purity of 99% to 99.99%.

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