Oxygen-deficient molybdenum vanadate nanorods, preparation method thereof and application thereof in cathode materials of aqueous zinc ion batteries
Patent Information
- Application Number
- CN202410208254.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-26
- Publication Date
- 2026-10-27
- Estimated Expiration
- 2044-02-26
AI Technical Summary
然而，在水系锌离子电池领域的研究尚属空白
[0018]本发明通过将MoV2O8纳米棒真空煅烧，在MoV2O8纳米棒中形成了适当氧缺陷，氧缺陷可以显著地降低层间应力和静电排斥，同时减少了金属离子插层过程中的迁移障碍，加快了反应动力学，这对提高电化学性能至关重要。因此，本发明通过氧缺陷的引入有效地提高了钒酸钼的电导率，加快了离子扩散速率，提供了更多的活性位点，同时本发明通过氧空位的引入使得MoV2O8纳米棒层间距变大，大的层间距提供了快速锌离子脱嵌的可行性。
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Figure CN118239516B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electrode materials technology, specifically to an oxygen-rich defect MoV2O8 nanorod, its preparation method, and its application in the cathode material of aqueous zinc-ion batteries. Background Technology
[0002] Compared to lithium-ion batteries using organic electrolytes, aqueous zinc-ion batteries offer advantages such as high safety, environmental friendliness, and low cost, making them highly promising for large-scale energy storage systems. The cathode material, a crucial component of zinc-ion batteries, directly impacts battery performance, including key performance indicators such as rate capability, cycle life, and energy density. Therefore, developing high-capacity, long-life cathode materials remains a significant challenge in zinc-ion battery research. In recent years, Prussian blue analogues, manganese-based compounds, and vanadium-based materials have been widely reported as cathode materials for zinc-ion batteries, with vanadium-based compounds attracting particular attention due to their diverse valence states and high theoretical capacity.
[0003] As is well known, transition metal oxides possess semiconductor properties. The d-electron layers of metal cations in metal oxides readily lose or gain electrons, exhibiting strong redox properties. In particular, ternary transition metal oxides, due to their complex chemical composition and synergistic effects, demonstrate superior electrochemical performance compared to single metal oxides. However, among the numerous ternary transition metal oxides, ternary metal vanadates have attracted significant research interest due to their high theoretical capacity, multiple valence states of V, and diverse structures. Importantly, MoV₂O₈, with its large interlayer spacing (0.97 nm) and high valence states of Mo and V, has been repeatedly reported in lithium-ion batteries and supercapacitors. Zheng et al. prepared porous MoV₂O₈ nanosheets as a negative electrode material for lithium-ion batteries, exhibiting excellent rate performance and cycle stability. This superior electrochemical performance is attributed to the synergistic effect of Mo and V on lithiation / delithiation. Yin et al. also reported that MoV₂O₈ nanorods exhibited excellent lithium storage performance in terms of specific capacity, rate performance, and cycle stability. This effectively demonstrates the potential advantages of MoV₂O₈ as an electrode material. However, research in the field of aqueous zinc-ion batteries is still lacking. Furthermore, like other transition metal oxides, MoV₂O₈ suffers from significant initial cycle capacity loss, poor reversibility, and low energy efficiency. Summary of the Invention
[0004] The purpose of this invention is to provide an oxygen-rich defect-laden MoV2O8 nanorod, its preparation method, and its application in aqueous zinc-ion battery cathode materials, thereby improving the electrochemical performance of MoV2O8 nanorod materials and promoting their application in aqueous zinc-ion battery cathode materials.
[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0006] This invention discloses a method for preparing oxygen-rich defect-laden MoV₂O₈ nanorods, comprising the following steps:
[0007] (1) C 10 H 16 MoO6 and C 10 H 14 O5V was dissolved in an ethylene glycol solution containing glycerol, and then subjected to a high-temperature hydrothermal reaction to obtain the precursor of MoV2O8.
[0008] (2) The precursor material of MoV2O8 obtained in step (1) is calcined in air atmosphere to obtain MoV2O8 nanorods.
[0009] (3) The MoV2O8 nanorods obtained in step (2) are calcined in vacuum to obtain oxygen-rich defect MoV2O8 nanorods.
[0010] As a preferred technical solution, in step (1), C 10 H 16 MoO6 and C 10 H 14 The molar ratio of O5V is 1:2.
[0011] As a preferred technical solution, the feature is that in step (1), the hydrothermal temperature is 120-200℃ and the reaction time is 10-48h.
[0012] As a preferred technical solution, in step (2), the calcination temperature is 400-800℃, the reaction time is 0.5-5h, and the heating rate during calcination is 1-10℃ / min.
[0013] As a preferred technical solution, in step (3), the calcination temperature is 200-800℃, the reaction time is 0.1-4h, and the heating rate during calcination is 1-10℃ / min.
[0014] The present invention also discloses an oxygen-defective MoV2O8 nanorod, which is prepared by the above-described method for preparing oxygen-defective MoV2O8 nanorods.
[0015] This invention also discloses the application of the above-mentioned oxygen-rich defect-laden MoV2O8 nanorods in the cathode material of aqueous zinc-ion batteries.
[0016] The present invention also discloses the application of the above-mentioned oxygen-rich defect-laden MoV2O8 nanorods in energy storage electrode materials.
[0017] The beneficial effects of this invention are:
[0018] This invention utilizes vacuum calcination of MoV₂O₈ nanorods to create appropriate oxygen vacancies within them. These oxygen vacancies significantly reduce interlayer stress and electrostatic repulsion, while also decreasing migration barriers during metal ion intercalation and accelerating reaction kinetics—crucial for improving electrochemical performance. Therefore, this invention effectively enhances the conductivity of molybdenum vanadate, accelerates ion diffusion, and provides more active sites through the introduction of oxygen vacancies. Furthermore, the introduction of oxygen vacancies increases the interlayer spacing of the MoV₂O₈ nanorods, enabling rapid zinc ion insertion / extraction.
[0019] The above advantages give oxygen-defect-rich MoV₂O₈ nanorods excellent electrochemical performance, 0.1 A g -1 After 100 cycles at a current density, the specific capacity still reaches 282.4 mAh g. -1 It has broad application prospects in aqueous zinc-ion batteries and other energy storage electrode materials. Attached Figure Description
[0020] Figure 1 Scanning electron microscope image of the oxygen-defective MoV2O8 nanorods prepared in Example 1;
[0021] Figure 2 The EPR spectrum of the oxygen-defective MoV2O8 nanorods prepared in Example 1;
[0022] Figure 3 The XRD pattern of the oxygen-defective MoV2O8 nanorods prepared in Example 1;
[0023] Figure 4 The oxygen-defect-rich MoV₂O₈ nanorods prepared in Example 1 were used as the positive electrode material for an aqueous zinc-ion battery at a current of 0.1 A g. -1 The following is a graph showing the cyclic performance.
[0024] Figure 5 The MoV₂O₈ nanorods prepared for Comparative Example 1 were used as the cathode material in an aqueous zinc-ion battery at a current of 0.1 Ag. -1 The following is a graph showing the cyclic performance. Detailed Implementation
[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to the accompanying drawings.
[0026] Example 1
[0027] (1) First, 1 mmol of C was heated by a stirrer in a water bath. 10 H 16 MoO6 and 2 mmol C 10 H14 MoV₂O₈ nanorods were dispersed in 35 mL of ethylene glycol containing 3.5 mL of glycerol. The mixture was then transferred to a 50 mL stainless steel autoclave and maintained at 200 °C for 24 h. After natural cooling, the precipitate was washed three times with water and ethanol and dried at 50 °C to obtain the precursor of MoV₂O₈ nanorods.
[0028] (2) The precursor obtained in step (1) is calcined in a tube furnace at 550°C in air atmosphere for 5 minutes. -1 After 3 hours, MoV2O8 nanorods were obtained.
[0029] (3) The MoV2O8 nanorods obtained in step (2) were calcined in a vacuum tube furnace for 0.5 h (500 °C, 5 °C min). -1 Natural cooling to room temperature yields oxygen-defect-rich MoV2O8 nanorods.
[0030] Comparative Example 1
[0031] (1) First, 1 mmol of C was heated by a stirrer in a water bath. 10 H 16 MoO6 and 2 mmol C 10 H 14 MoV₂O₈ nanorods were dispersed in 35 mL of ethylene glycol containing 3.5 mL of glycerol. The mixture was then transferred to a 50 mL stainless steel autoclave and maintained at 200 °C for 24 h. After natural cooling, the precipitate was washed three times with water and ethanol and dried at 50 °C to obtain the precursor of MoV₂O₈ nanorods.
[0032] (2) The precursor obtained in step (1) is calcined in a tube furnace at 550°C in air atmosphere for 5 minutes. -1 After 3 hours, MoV2O8 nanorods were obtained.
[0033] Figure 1 The image shows a scanning electron microscope image of the oxygen-defective MoV2O8 nanorods obtained in Example 1. The morphology of this material is a uniformly dispersed nanorod.
[0034] Figure 2 The image shows the EPR spectrum of the oxygen-defect-rich MoV₂O₈ nanorods obtained in Example 1. Figure 2 It can be seen that the MoV2O8 nanorods exhibit a stronger oxygen vacancy-related EPR signal at G=2.003, which indicates that a large number of oxygen vacancies are generated.
[0035] Figure 3 The image shows the XRD pattern of the oxygen-defective MoV2O8 nanorods obtained in Example 1. The results show that the diffraction peaks of the MoV2O8 nanorods match the peaks on the standard card.
[0036] Button batteries were assembled using the MoV2O8 nanorod materials prepared in Example 1 and Comparative Example 1, and the cycling performance of the materials was tested:
[0037] The MoV₂O₈ nanorods prepared in Example 1 and Comparative Example 1, acetylene black, and polyvinylidene fluoride (PVDF) were weighed at a mass ratio of 7:2:1, ground uniformly, and then mixed with an appropriate amount of N-methylpyrrolidone (NMP). The slurry was then coated onto carbon paper and dried in an oven at 50°C for 12 hours. The coated MoV₂O₈ nanorods were used as the positive electrode, zinc foil as the negative electrode, a glass fiber membrane as the separator, and 3M Zn(CF₃SO₃)₂ as the electrolyte to assemble 2032 coin cells. The assembled cells were then subjected to electrochemical performance testing on a LAND battery testing system.
[0038] Figure 4 The oxygen-defect-rich MoV₂O₈ nanorods prepared in Example 1 were used as the positive electrode material for an aqueous zinc-ion battery at a current of 0.1 A g. -1 The cycling performance graph below shows that the oxygen-defect-rich MoV2O8 nanorod electrode material exhibits good performance at 0.1 A g. -1 After 100 cycles at a current density, the specific capacity still reaches 282.4 mAh g. -1 .
[0039] Figure 5 The MoV₂O₈ nanorods prepared for Comparative Example 1 were used as the cathode material in an aqueous zinc-ion battery at a current of 0.1 Ag. -1 The cycling performance graph below shows that the specific capacity of the MoV2O8 nanorod electrode material in Comparative Example 1 is much lower than that of the oxygen-rich defect-laden MoV2O8 nanorod electrode material in Example 1.
[0040] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.
Claims
1. A method for preparing oxygen-rich defect-laden MoV₂O₈ nanorods, characterized in that: Includes the following steps: (1) Take 1 mmol of C 10 H 16 MoO6 and 2 mmol C 10 H 14 O5V was dissolved in 35 mL of ethylene glycol solution containing 3.5 mL of glycerol, and then subjected to a high-temperature hydrothermal reaction at 200 °C for 24 h to obtain the precursor of MoV2O8. (2) The precursor material of MoV2O8 obtained in step (1) was calcined in air atmosphere at a calcination temperature of 550℃ for 3 h and a heating rate of 5℃ / min during calcination to obtain MoV2O8 nanorods. (3) The MoV2O8 nanorods obtained in step (2) were calcined in vacuum at a temperature of 500℃ for 0.5h and a heating rate of 5℃ / min to obtain oxygen-rich defect MoV2O8 nanorods.
2. A MoV2O8 nanorod with oxygen-rich defects, characterized in that: The MoV2O8 nanorods with oxygen-rich defects as described in claim 1 are prepared.
3. The application of the oxygen-rich defect-laden MoV2O8 nanorods as described in claim 2 in the cathode material of aqueous zinc-ion batteries.