A method for preparing fibrous zinc-ion pre-intercalated hydrated vanadium pentoxide and its application in zinc-ion batteries.

Abstract

This invention discloses a simple method for preparing fibrous zinc-ion pre-intercalated hydrated vanadium pentoxide and its application in zinc-ion batteries. The chemical composition of the cation-intercalated hydrated vanadium pentoxide is Zn. x V₂O₅·nH₂O, where x is 0.001–0.5 and n is 0.1–3. This invention involves immersing a vanadium-based compound in a solution containing zinc ions and a surfactant, reacting it at a certain temperature for a period of time. The zinc-ion pre-intercalated hydrated vanadium pentoxide obtained by this method is fibrous, and its size can be adjusted with reaction time, temperature, and the type and concentration of the immersion solution. The above preparation method features mild reaction conditions and a simple process; the obtained zinc-ion pre-intercalated hydrated vanadium pentoxide, when used as a cathode material in aqueous zinc-ion batteries, exhibits excellent cycle stability.

Description

Technical Field

[0001] This invention belongs to the field of zinc-ion battery cathode materials, specifically relating to a method for preparing fibrous zinc-ion pre-intercalated hydrated vanadium pentoxide and its application in zinc-ion batteries. Background Technology

[0002] To overcome the shortage of traditional fossil fuels and alleviate the environmental crisis, there is an urgent need to develop and utilize renewable clean energy sources (such as solar, geothermal, and wind power). The efficient transportation and storage of renewable clean energy are crucial. Energy storage devices that convert chemical energy into electrical energy are relatively mature, and effective storage methods for intermittent clean energy can achieve large-scale energy transmission. Rechargeable lithium-ion batteries (LIBs) have achieved great success due to their high energy density, long cycle life, and small size, becoming the preferred energy storage device for electronic products. However, due to lithium resource shortages, high costs, toxic electrolytes, and safety concerns, the continued widespread application of lithium-ion batteries is limited. Therefore, developing new rechargeable secondary batteries with low cost, good cycle performance, and safety and environmental friendliness has become a focus of attention. Zinc, aluminum, magnesium, and other multivalent ion batteries, with multiple electrons participating in redox reactions during charging and discharging, can achieve higher energy densities and have received increasing attention in recent years. Metallic zinc possesses advantages such as high theoretical capacity, low redox potential (0.76 V vs. SHE), high natural abundance, and small hydrated ion radius, making aqueous zinc-ion batteries (AZIBs) more suitable as an ideal green energy storage system. Furthermore, replacing the alkaline electrolyte with a mild neutral pH (or slightly acidic) solution can solve the problem of zinc dendrite formation in alkaline zinc batteries, thereby reducing operating costs and negative environmental impacts. However, even with the basic solutions to the negative electrode and electrolyte issues, many key problems remain to be addressed for zinc-ion batteries. Generally, the inherently poor conductivity and strong electrostatic interactions of cathode materials lead to poor cycle stability and slow kinetics in aqueous zinc-ion batteries. Much cathode material dissolves in the electrolyte, causing irreversible capacity loss and poor cycle stability. In addition, cathode materials undergo phase transitions during cycling, resulting in large volume changes, structural collapse, and poor stability. Therefore, developing a structurally stable, high-performance cathode material is crucial for the commercial application of aqueous zinc-ion batteries.

[0003] In recent years, vanadium-based cathode materials have mainly included layered or tunnel-like vanadium oxides, vanadates, and Nasicon-type vanadium-based compounds. Dipan Kundu et al. reported in *Nature Energy*, Volume 1, 2016, page 16119, on the synthesis of a Zn alloy at 180℃ using a hydrothermal method. 0.25 V₂O₅·nH₂O layered material, used as the positive electrode in aqueous zinc-ion batteries, exhibits excellent electrochemical performance (at a current density of 300 mA g⁻¹). 1 Below, the initial capacity reached 282mAh g. 1 However, its preparation method is complex and difficult to use on a large scale. Therefore, developing a simple and easily scalable preparation method to synthesize zinc ion pre-intercalated hydrated vanadium pentoxide is one of the key scientific issues for the practical application of zinc-ion batteries. Summary of the Invention

[0004] The purpose of this invention is to solve the current problems in the preparation of high-performance cathode materials for zinc-ion batteries. It provides a simple, large-scale method for synthesizing fibrous zinc-ion pre-intercalated hydrated vanadium pentoxide, and applies it to the cathode of zinc-ion batteries, thereby ensuring the stability of the charge-discharge process and the high capacity of the zinc-ion battery.

[0005] One of the objectives of this invention is to prepare zinc ion pre-intercalated hydrated vanadium pentoxide, which exhibits a fibrous morphology.

[0006] First, the chemical composition of the zinc ion pre-intercalated hydrated vanadium pentoxide is Zn. x V₂O₅·nH₂O, where x is 0.001~0.5 and n is 0.1~3. The steps are as follows: First, the vanadium-based compound is dispersed in an aqueous solution or a mixed solution of water and ethanol containing zinc ions and a surfactant; then, the above solution is stirred and reacted for a period of time at a certain temperature; after filtration, washing, and drying, fibrous zinc ion pre-intercalated hydrated vanadium pentoxide is obtained.

[0007] Furthermore, in the above technical solution, the length of the fibrous zinc ion pre-intercalated hydrated vanadium pentoxide is 100 nm – 50 μm, and the width of the fibrous zinc ion pre-intercalated hydrated vanadium pentoxide is 20 nm – 500 nm; preferably, the length is 200 nm – 800 nm, and preferably the width is 50 nm – 800 nm.

[0008] Furthermore, in the above technical solution, the vanadium-based compound is any vanadium-containing oxide, including vanadium monoxide (VO), vanadium trioxide (V₂O₃), vanadium dioxide (VO₂), vanadium pentoxide (V₂O₅), vanadium trioxide (V₃O₈), and vanadium hexadecyloxide (V₆O₅). 13 M is one or more of the following: orthovanadate (MVO4), pyrovanadate (MV2O7), and metavanadate (MVO3), wherein M is an ammonium ion (NH4+). + Sodium ions (Na) + ), potassium ions (K) + ), iron ions (Fe 2+ / Fe 3+ ), calcium ions (Ca 2+) or bismuth ions (Bi 3+ The preferred vanadium-based oxide is V2O5.

[0009] Furthermore, in the above technical solution, the zinc salt includes zinc chloride (ZnCl2), zinc sulfate (ZnSO4), zinc nitrate (Zn(NO3)2), zinc chlorate (Zn(ClO4)2), zinc fluoroborate (Zn(BF4)2), zinc fluorosilicate (ZnSiF6), zinc acetate ((CH3COO)2Zn), and zinc gluconate (C 12 H 22 O 14 One or more of the following zinc salts: zinc(n) (Zn); the preferred zinc salt is zinc sulfate. The concentration of the zinc salt in the aqueous solution or mixed solution is 0.01 mol / L - 4 mol / L.

[0010] Furthermore, in the above technical solution, the surfactant is one or more of the following: stearic acid, sodium dodecylbenzenesulfonate, sodium dodecyl sulfate, polyvinylpyrrolidone, alkyl glucoside, fatty acid glycerides, fatty acid sorbitan, polysorbate, etc.; the preferred surfactant is sodium dodecyl sulfate. The concentration of the surfactant in the solution is greater than 0 g / L and less than 10 g / L.

[0011] Furthermore, in the above technical solution, different ratios of alcohol and water will adjust the morphology of the self-conversion product, with the volume ratio of ethanol to water being 0.01–2; the preferred volume ratio of ethanol to water is 0.2–1.

[0012] Furthermore, in the above technical solution, the stirring temperature is -5℃–100℃; preferably, the stirring temperature is 20℃–60℃.

[0013] Furthermore, in the above technical solution, the stirring time is 1 day to 100 days; the preferred stirring time is 5 days to 20 days.

[0014] Furthermore, in the above technical solutions, the drying methods include vacuum drying, forced-air drying, freeze drying, spray drying, and fluidized bed drying; the preferred drying method is freeze drying.

[0015] The second objective of this invention is to provide an application of fibrous zinc ion pre-intercalated hydrated vanadium pentoxide in the positive electrode of a zinc-ion battery.

[0016] Furthermore, in the above technical solution, the open layered structure of the zinc ion pre-intercalated hydrated vanadium pentoxide material is conducive to the transfer and diffusion of zinc ions, and can be used as a positive electrode material for aqueous zinc-ion batteries.

[0017] The fibrous zinc ion pre-intercalated hydrated vanadium pentoxide prepared by the above method can be used in the positive electrode of aqueous zinc ion batteries.

[0018] Beneficial effects: This invention enables the preparation of fibrous zinc-ion pre-intercalated hydrated vanadium pentoxide, which is a cathode material for aqueous zinc-ion batteries with excellent electrochemical performance. Furthermore, this method involves simple equipment, convenient operation, and low cost. The prepared material also exhibits excellent electrochemical properties, which are beneficial for the charge-discharge stability and high capacity of zinc-ion batteries.

[0019] (1) The fibrous zinc ion pre-intercalated hydrated vanadium pentoxide prepared by this invention has an open layered framework structure, which is conducive to the transfer and diffusion of zinc ions. As a positive electrode of zinc-ion batteries, it can provide excellent electrochemical reversibility, high specific capacity, huge energy density, and long cycle performance.

[0020] (2) The present invention selects different vanadium-based compound precursors, which can adjust the interlayer spacing of hydrated vanadium pentoxide and improve the structural stability of hydrated vanadium pentoxide, thereby solving the problems of capacity decay during cycling and poor performance at high current density.

[0021] (3) The preparation method of the present invention is simple, easy to operate, can be prepared in large quantities, and is universally applicable. Attached Figure Description

[0022] Figure 1 This is an electron micrograph of the reactant V2O5 and the product fibrous zinc ion pre-intercalated hydrated vanadium pentoxide in Example 1 of the present invention. Figure 2 The XRD pattern of reactant V2O5 and product fibrous zinc ion pre-intercalated hydrated vanadium pentoxide in Example 1 of the present invention; Figure 3 This is a cyclic stability test curve of fibrous zinc ion pre-intercalated hydrated vanadium pentoxide in Example 1; Figure 4 This is an electron microscope image of the fibrous zinc ion pre-intercalated hydrated vanadium pentoxide prepared in Examples 2-11. Detailed Implementation

[0023] The following embodiments will further illustrate the present invention, but are not intended to limit the invention. Example 1 According to the technical solution of this invention, the vanadium-based material selected is V₂O₅, and the scanning electron microscope image of V₂O₅ is shown in... Figure 1 As shown in (a), the morphology consists of short, coarse particles with a particle size ranging from 100 nm to 200 nm. The XRD pattern of V₂O₅ is shown in [reference needed]. Figure 2 ( Figure 2As given in section ①, 136.3 g of ZnCl2 sample powder was weighed and dissolved in 1 L of a mixed solvent of ethanol and water (volume ratio 1:1), and sodium dodecylbenzenesulfonate, a surfactant, was added to prepare a 1 mol / L ZnCl2 solution. 100 g of V2O5 was weighed and dispersed in 1 L of the 1 mol / L ZnCl2 solution. The V2O5 was ultrasonically dispersed for 1 h to ensure uniform dispersion, forming a suspension. The suspension was then placed on a magnetic stirrer and stirred for 30 days. After the specified stirring time, the suspension was centrifuged, and the precipitate was collected. The precipitate was then dried to obtain zinc ion pre-intercalated hydrated vanadium pentoxide (ZnCl2). 0.2 (V₂O₅·nH₂O), the x value was obtained by inductively coupled plasma analyzer. Zn 0.2 Scanning electron microscopy image of V2O5·nH2O in Figure 1 As given in (b), XRD in Figure 2 ( Figure 2 As shown in section ②), electron microscopy results show that the precursor vanadium-based material successfully transformed into fibrous zinc ion pre-intercalated hydrated vanadium pentoxide material.

[0024] Electrode sheets were prepared according to a mass ratio of active material: conductive agent: binder = 7:2:1. The active material (Zn) prepared in this embodiment was then used... 0.2 V₂O₅·nH₂O and a conductive agent (acetylene black) were ground in an agate mortar, and then polyvinylidene fluoride (PVDF) and N-methylpyrrolidone were added and ground into a black paste. The resulting electrode material was placed on a current collector and pressed into an electrode sheet of a certain thickness. The electrode sheet was then vacuum dried at 80 °C for 12 h, and then punched into small round discs with a diameter of 14 mm for later use. The prepared electrode sheet was used as the positive electrode, zinc metal as the negative electrode, 2 mol / L ZnSO₄ as the electrolyte, glass fiber as the separator, and stainless steel foil as the current collector. A button cell was assembled, and its constant current charge-discharge performance was tested using a battery performance tester. 0.2 The initial charge-discharge results of V2O5·nH2O at a current density of 500 mA / g show... Figure 3 In the middle, Zn 0.2 The initial charge-discharge capacity of the V₂O₅·nH₂O electrode was 412 mA·h / g. After 100 cycles of stability testing, the Zn… x The discharge specific capacity of the V2O5·nH2O electrode is 375 mA·h / g, and the capacity retention rate is 91%.

[0025] Example 2 According to the technical solution of this invention, V₂O₅ is selected as the vanadium-based material. 232.28g of zinc chlorate sample powder is weighed and dissolved in 1L of a 2:1 mixture of ethanol and water, and sodium dodecylbenzenesulfonate, a surfactant, is added to prepare a 1mol / L Zn(ClO₃)₂ solution. 100g of V₂O₅ is weighed and dispersed in 1L of the 1mol / L Zn(ClO₃)₂ solution. The solution is ultrasonically dispersed for 1 hour using an ultrasonic probe to ensure uniform dispersion of V₂O₅, forming a suspension. The suspension is then placed on a magnetic stirrer and stirred for 15 days. After stirring for the specified time, the suspension is centrifuged, and the precipitate is collected. The precipitate is then dried to obtain zinc ion pre-intercalated hydrated vanadium pentoxide (Zn₂O₅). 0.1 (V₂O₅·nH₂O), the x value was obtained by inductively coupled plasma analyzer. Zn 0.1 Scanning electron microscopy image of V2O5·nH2O in Figure 4 As shown in (a), electron microscopy results show that the precursor vanadium-based material successfully self-transformed into fibrous zinc ion pre-intercalated hydrated vanadium pentoxide material.

[0026] Electrode sheets were prepared according to a mass ratio of active material: conductive agent: binder = 7:2:1. The active material (Zn) prepared in this embodiment was then used... 0.1 V2O5·nH2O) and a conductive agent (acetylene black) were ground in an agate mortar, and then polyvinylidene fluoride (PVDF) and N-methylpyrrolidone were added and ground into a black paste. The resulting electrode material was placed on a current collector and pressed into an electrode sheet of a certain thickness. The electrode sheet was then vacuum dried at 80 °C for 12 h, and then punched into small round discs with a diameter of 14 mm for later use. The prepared electrode sheet was used as the positive electrode, zinc metal as the negative electrode, 2 mol / L ZnSO4 as the electrolyte, glass fiber as the separator, and stainless steel foil as the current collector. A button cell was assembled and its constant current charge-discharge performance was tested using a battery performance tester. At a current density of 500 mA / g, Zn 0.1 After 100 cycles of stability testing, the V2O5·nH2O electrode was subjected to Zn 0.1 The discharge specific capacity of the V2O5·nH2O electrode is 370 mA·h / g, and the capacity retention rate is 91.1%.

[0027] Example 3 According to the technical solution of this invention, V₂O₅ is selected as the vanadium-based material. 232.28g of zinc chlorate sample powder is weighed and dissolved in 1L of a 1:2 mixture of ethanol and water, and sodium dodecyl sulfate (SO₃)₂ surfactant is added to prepare a 1 mol / L Zn(ClO₃)₂ solution. 100g of V₂O₅ is weighed and dispersed in 1L of the 1 mol / L Zn(ClO₃)₂ solution. The solution is ultrasonically dispersed for 1 hour to ensure uniform dispersion of V₂O₅, forming a suspension. The suspension is then placed on a magnetic stirrer and stirred for 45 days. After stirring for the specified time, the suspension is centrifuged, and the precipitate is collected. The precipitate is then dried to obtain zinc ion pre-intercalated hydrated vanadium pentoxide (Zn₂O₅). 0.25 (V₂O₅·nH₂O), the x value was obtained by inductively coupled plasma analyzer. Zn 0.25 Scanning electron microscopy image of V2O5·nH2O in Figure 4 As shown in (b), electron microscopy results show that the precursor vanadium-based material successfully self-transformed into fibrous zinc ion pre-intercalated hydrated vanadium pentoxide material.

[0028] Electrode sheets were prepared according to a mass ratio of active material: conductive agent: binder = 7:2:1. The active material (Zn) prepared in this embodiment was then used... 0.25 V2O5·nH2O) and a conductive agent (acetylene black) were ground in an agate mortar, and then polyvinylidene fluoride (PVDF) and N-methylpyrrolidone were added and ground into a black paste. The resulting electrode material was placed on a current collector and pressed into an electrode sheet of a certain thickness. The electrode sheet was then vacuum dried at 80 °C for 12 h, and then punched into small round discs with a diameter of 14 mm for later use. The prepared electrode sheet was used as the positive electrode, zinc metal as the negative electrode, 2 mol / L ZnSO4 as the electrolyte, glass fiber as the separator, and stainless steel foil as the current collector. A button cell was assembled, and its constant current charge-discharge performance was tested using a battery performance tester. At a current density of 500 mA / g, Zn 0.25 After 100 cycles of stability testing, the V2O5·nH2O electrode was subjected to Zn 0.25 The discharge specific capacity of the V2O5·nH2O electrode is 388 mA·h / g, and the capacity retention rate is 92%.

[0029] Example 4 According to the technical solution of this invention, V₂O₅ is selected as the vanadium-based material. 161.45g of ZnSO₄ sample powder is weighed and dissolved in 1L of a 1:1 mixture of ethanol and water, and sodium dodecylbenzenesulfonate, a surfactant, is added to prepare a 1mol / L ZnSO₄ solution. 100g of V₂O₅ is weighed and dispersed in 1L of the 1mol / L ZnSO₄ solution. The V₂O₅ is ultrasonically dispersed for 1 hour to ensure uniform dispersion, forming a suspension. The suspension is then placed on a magnetic stirrer and stirred for 60 days. After stirring for the specified time, the suspension is centrifuged, and the precipitate is collected. The precipitate is then dried to obtain zinc ion pre-intercalated hydrated vanadium pentoxide (ZnSO₄). 0.3 The x value of V2O5·nH2O was obtained by inductively coupled plasma analyzer. Zn 0.3 Scanning electron microscopy image of V2O5·nH2O in Figure 4 As shown in (c), electron microscopy results show that the precursor vanadium-based material successfully self-transformed into fibrous zinc ion pre-intercalated hydrated vanadium pentoxide material.

[0030] Electrode sheets were prepared according to a mass ratio of active material: conductive agent: binder = 7:2:1. The active material (Zn) prepared in this embodiment was then used... 0.3 V2O5·nH2O) and a conductive agent (acetylene black) were ground in an agate mortar, and then polyvinylidene fluoride (PVDF) and N-methylpyrrolidone were added and ground into a black paste. The resulting electrode material was placed on a current collector and pressed into an electrode sheet of a certain thickness. The electrode sheet was then vacuum dried at 80 °C for 12 h, and then punched into small round discs with a diameter of 14 mm for later use. The prepared electrode sheet was used as the positive electrode, zinc metal as the negative electrode, 2 mol / L ZnSO4 as the electrolyte, glass fiber as the separator, and stainless steel foil as the current collector. A button cell was assembled and its constant current charge-discharge performance was tested using a battery performance tester. At a current density of 500 mA / g, Zn 0.3 After 100 cycles of stability testing, the V2O5·nH2O electrode was subjected to Zn 0.3 The discharge specific capacity of the V2O5·nH2O electrode is 390 mA·h / g, and the capacity retention rate is 92.6%.

[0031] Example 5 According to the technical solution of this invention, VO2 is selected as the vanadium-based material. 189.4g of Zn(NO3)2 sample powder is weighed and dissolved in 1L of a 1:1 mixture of ethanol and water, and sodium dodecylbenzenesulfonate, a surfactant, is added to prepare a 1mol / L Zn(NO3)2 solution. 100g of VO2 is weighed and dispersed in 1L of the 1mol / L Zn(NO3)2 solution. The VO2 is ultrasonically dispersed for 1 hour using an ultrasonic probe to ensure uniform dispersion and form a suspension. The suspension is then placed on a magnetic stirrer and stirred for 50 days. After stirring for the specified time, the suspension is centrifuged, and the precipitate is collected. The precipitate is then dried to obtain zinc ion pre-intercalated hydrated vanadium pentoxide (Zn2). 0.28 (V₂O₅·nH₂O), the x value was obtained by inductively coupled plasma analyzer. Zn 0.28 Scanning electron microscopy image of V2O5·nH2O in Figure 4 As shown in (d), electron microscopy results show that the precursor vanadium-based material successfully transformed into fibrous zinc ion pre-intercalated hydrated vanadium pentoxide material.

[0032] Electrode sheets were prepared according to a mass ratio of active material: conductive agent: binder = 7:2:1. The active material (Zn) prepared in this embodiment was then used... x V2O5·nH2O) and a conductive agent (acetylene black) were ground in an agate mortar, and then polyvinylidene fluoride (PVDF) and N-methylpyrrolidone were added and ground into a black paste. The resulting electrode material was placed on a current collector and pressed into an electrode sheet of a certain thickness. The electrode sheet was then vacuum dried at 80 °C for 12 h, and then punched into small round discs with a diameter of 14 mm for later use. The prepared electrode sheet was used as the positive electrode, zinc metal as the negative electrode, 2 mol / L ZnSO4 as the electrolyte, glass fiber as the separator, and stainless steel foil as the current collector. A button cell was assembled and its constant current charge-discharge performance was tested using a battery performance tester. At a current density of 500 mA / g, Zn 0.28 After 100 cycles of stability testing, the V2O5·nH2O electrode was subjected to Zn 0.28 The discharge specific capacity of the V2O5·nH2O electrode is 379 mA·h / g, and the capacity retention rate is 92.2%.

[0033] Example 6 According to the technical solution of this invention, V₂O₃ is selected as the vanadium-based material. 239g of Zn(BF₄)₂ sample powder is weighed and dissolved in 1L of a 1:1 mixture of ethanol and water, and sodium dodecyl sulfate (SO₄)₂ surfactant is added to prepare a 1mol / L Zn(BF₄)₂ solution. 100g of V₂O₃ is weighed and dispersed in 1L of the 1mol / L Zn(BF₄)₂ solution. The solution is ultrasonically dispersed for 1 hour using an ultrasonic probe to ensure uniform dispersion of V₂O₃, forming a suspension. The suspension is then placed on a magnetic stirrer and stirred for 40 days. After stirring for the specified time, the suspension is centrifuged, and the precipitate is collected. The precipitate is then dried to obtain zinc ion pre-intercalated hydrated vanadium pentoxide (Zn₂O₃). 0.26 (V₂O₅·nH₂O), the x value was obtained by inductively coupled plasma analyzer. Zn 0.26 Scanning electron microscopy image of V2O5·nH2O in Figure 4 As shown in (e), electron microscopy results show that the precursor vanadium-based material successfully self-transformed into fibrous zinc ion pre-intercalated hydrated vanadium pentoxide material.

[0034] Electrode sheets were prepared according to a mass ratio of active material: conductive agent: binder = 7:2:1. The active material (Zn) prepared in this embodiment was then used... 0.26 V2O5·nH2O) and a conductive agent (acetylene black) were ground in an agate mortar, and then polyvinylidene fluoride (PVDF) and N-methylpyrrolidone were added and ground into a black paste. The resulting electrode material was placed on a current collector and pressed into an electrode sheet of a certain thickness. The electrode sheet was then vacuum dried at 80 °C for 12 h, and then punched into small round discs with a diameter of 14 mm for later use. The prepared electrode sheet was used as the positive electrode, zinc metal as the negative electrode, 2 mol / L ZnSO4 as the electrolyte, glass fiber as the separator, and stainless steel foil as the current collector. A button cell was assembled and its constant current charge-discharge performance was tested using a battery performance tester. At a current density of 500 mA / g, Zn 0.26 After 100 cycles of stability testing, the V2O5·nH2O electrode was subjected to Zn 0.26 The discharge specific capacity of the V2O5·nH2O electrode is 374 mA·h / g, and the capacity retention rate is 90.1%.

[0035] Example 7 According to the technical solution of this invention, VO2 is selected as the vanadium-based material. Weigh C... 12 H 22 O 14 455.7 g of Zn sample powder was dissolved in 1 L of a 1:1 mixture of ethanol and water, and sodium dodecylbenzenesulfonate, a surfactant, was added to prepare a 1 mol / L C solution. 12H 22 O 14 Zn solution. Weigh 100g of VO2 and disperse it in 1L of 1mol / L C solution. 12 H 22 O 14 In a Zn solution, VO2 was ultrasonically dispersed for 1 hour to ensure uniform dispersion and form a suspension. The suspension was then placed on a magnetic stirrer and stirred for 80 days. After the specified stirring time, the suspension was centrifuged, and the precipitate was collected. The precipitate was then dried to obtain zinc ion pre-intercalated hydrated vanadium pentoxide (Zn). 0.35 (V₂O₅·nH₂O), the x value was obtained by inductively coupled plasma analyzer. Zn 0.35 Scanning electron microscopy image of V2O5·nH2O in Figure 4 As shown in (f), electron microscopy results show that the precursor vanadium-based material successfully self-transformed into fibrous zinc ion pre-intercalated hydrated vanadium pentoxide material.

[0036] Electrode sheets were prepared according to a mass ratio of active material: conductive agent: binder = 7:2:1. The active material (Zn) prepared in this embodiment was then used... 0.35 V2O5·nH2O) and a conductive agent (acetylene black) were ground in an agate mortar, and then polyvinylidene fluoride (PVDF) and N-methylpyrrolidone were added and ground into a black paste. The resulting electrode material was placed on a current collector and pressed into an electrode sheet of a certain thickness. The electrode sheet was then vacuum dried at 80 °C for 12 h, and then punched into small round discs with a diameter of 14 mm for later use. The prepared electrode sheet was used as the positive electrode, zinc metal as the negative electrode, 2 mol / L ZnSO4 as the electrolyte, glass fiber as the separator, and stainless steel foil as the current collector. A button cell was assembled and its constant current charge-discharge performance was tested using a battery performance tester. At a current density of 500 mA / g, Zn 0.35 After 100 cycles of stability testing, the V2O5·nH2O electrode was subjected to Zn 0.35 The discharge specific capacity of the V2O5·nH2O electrode is 389 mA·h / g, and the capacity retention rate is 92.8%.

[0037] Example 8 According to the technical solution of this invention, V₂O₅ is selected as the vanadium-based material. 183.4 g of (CH₃COO)₂Zn sample powder is weighed and dissolved in 1 L of a 1:1 mixture of ethanol and water, and sodium dodecyl sulfate (DSS) is added to prepare a 1 mol / L (CH₃COO)₂Zn solution. 100 g of V₂O₅ is weighed and dispersed in 1 L of the 1 mol / L (CH₃COO)₂Zn solution. The solution is ultrasonically dispersed for 1 hour to ensure uniform dispersion of V₂O₅, forming a suspension. The suspension is then stirred on a magnetic stirrer for 20 days. After the specified stirring time, the suspension is centrifuged, and the precipitate is collected. The precipitate is then dried to obtain zinc ion pre-intercalated hydrated vanadium pentoxide (Zn₂O₅). 0.16 (V₂O₅·nH₂O), the x value was obtained by inductively coupled plasma analyzer. Zn 0.16 Scanning electron microscopy image of V2O5·nH2O in Figure 4 As shown in (g), electron microscopy results show that the precursor vanadium-based material successfully self-transformed into fibrous zinc ion pre-intercalated hydrated vanadium pentoxide material.

[0038] Electrode sheets were prepared according to a mass ratio of active material: conductive agent: binder = 7:2:1. The active material (Zn) prepared in this embodiment was then used... 0.16 V2O5·nH2O) and a conductive agent (acetylene black) were ground in an agate mortar, and then polyvinylidene fluoride (PVDF) and N-methylpyrrolidone were added and ground into a black paste. The resulting electrode material was placed on a current collector and pressed into an electrode sheet of a certain thickness. The electrode sheet was then vacuum dried at 80 °C for 12 h, and then punched into small round discs with a diameter of 14 mm for later use. The prepared electrode sheet was used as the positive electrode, zinc metal as the negative electrode, 2 mol / L ZnSO4 as the electrolyte, glass fiber as the separator, and stainless steel foil as the current collector. A button cell was assembled, and its constant current charge-discharge performance was tested using a battery performance tester. At a current density of 500 mA / g, Zn 0.16 After 100 cycles of stability testing, the V2O5·nH2O electrode was subjected to Zn 0.16 The discharge specific capacity of the V2O5·nH2O electrode is 380 mA·h / g, and the capacity retention rate is 90%.

[0039] Example 9 According to the technical solution of this invention, VO2 is selected as the vanadium-based material. 136.3g of ZnCl2 sample powder is weighed and dissolved in 1L of a 1:1 mixture of ethanol and water, and the surfactant alkyl glucoside is added to prepare a 1mol / L ZnCl2 solution. 100g of VO2 is weighed and dispersed in 1L of the 1mol / L ZnCl2 solution. The VO2 is ultrasonically dispersed for 1 hour using an ultrasonic probe to ensure uniform dispersion and form a suspension. The suspension is then placed on a magnetic stirrer and stirred for 60 days. After stirring for the specified time, the suspension is centrifuged, and the precipitate is collected. The precipitate is then dried to obtain zinc ion pre-intercalated hydrated vanadium pentoxide (ZnCl2). 0.3 (V₂O₅·nH₂O), the x value was obtained by inductively coupled plasma analyzer. Zn 0.3 Scanning electron microscopy image of V2O5·nH2O in Figure 4 As shown in (h), electron microscopy results show that the precursor vanadium-based material successfully self-transformed into fibrous zinc ion pre-intercalated hydrated vanadium pentoxide material.

[0040] Electrode sheets were prepared according to a mass ratio of active material: conductive agent: binder = 7:2:1. The active material (Zn) prepared in this embodiment was then used... 0.3 V2O5·nH2O) and a conductive agent (acetylene black) were ground in an agate mortar, and then polyvinylidene fluoride (PVDF) and N-methylpyrrolidone were added and ground into a black paste. The resulting electrode material was placed on a current collector and pressed into an electrode sheet of a certain thickness. The electrode sheet was then vacuum dried at 80 °C for 12 h, and then punched into small round discs with a diameter of 14 mm for later use. The prepared electrode sheet was used as the positive electrode, zinc metal as the negative electrode, 2 mol / L ZnSO4 as the electrolyte, glass fiber as the separator, and stainless steel foil as the current collector. A button cell was assembled and its constant current charge-discharge performance was tested using a battery performance tester. At a current density of 500 mA / g, Zn 0.3 After 100 cycles of cyclic stability testing, the V2O5·nH2O electrode showed Zn... 0.3 The discharge specific capacity of the V2O5·nH2O electrode is 398 mA·h / g, and the capacity retention rate is 94.5%.

[0041] Example 10 According to the technical solution of this invention, V₂O₃ is selected as the vanadium-based material. 136.3g of ZnCl₂ sample powder is weighed and dissolved in 1L of a 1:1 mixture of ethanol and water, and sodium dodecylbenzenesulfonate, a surfactant, is added to prepare a 1mol / L ZnCl₂ solution. 100g of V₂O₃ is weighed and dispersed in 1L of the 1mol / L ZnCl₂ solution. The solution is ultrasonically dispersed for 1 hour using an ultrasonic probe to ensure uniform dispersion of V₂O₃, forming a suspension. The suspension is then placed on a magnetic stirrer and stirred for 15 days. After stirring for the specified time, the suspension is centrifuged, and the precipitate is collected. The precipitate is then dried to obtain zinc ion pre-intercalated hydrated vanadium pentoxide (Zn₂O₃). 0.1 (V₂O₅·nH₂O), the x value was obtained by inductively coupled plasma analyzer. Zn 0.1 Scanning electron microscopy image of V2O5·nH2O in Figure 4 As given in i), electron microscopy results show that the precursor vanadium-based material successfully self-transformed into fibrous zinc ion pre-intercalated hydrated vanadium pentoxide material.

[0042] Electrode sheets were prepared according to a mass ratio of active material: conductive agent: binder = 7:2:1. The active material (Zn) prepared in this embodiment was then used... 0.1 V2O5·nH2O) and a conductive agent (acetylene black) were ground in an agate mortar, and then polyvinylidene fluoride (PVDF) and N-methylpyrrolidone were added and ground into a black paste. The resulting electrode material was placed on a current collector and pressed into an electrode sheet of a certain thickness. The electrode sheet was then vacuum dried at 80 °C for 12 h, and then punched into small round discs with a diameter of 14 mm for later use. The prepared electrode sheet was used as the positive electrode, zinc metal as the negative electrode, 2 mol / L ZnSO4 as the electrolyte, glass fiber as the separator, and stainless steel foil as the current collector. A button cell was assembled and its constant current charge-discharge performance was tested using a battery performance tester. At a current density of 500 mA / g, Zn 0.1 After 100 cycles of stability testing, the V2O5·nH2O electrode exhibited a discharge specific capacity of 370 mA·h / g and a capacity retention rate of 90.2%.

[0043] Example 11 According to the technical solution of this invention, NH4VO3 is selected as the vanadium-based material. 136.3g of ZnCl2 sample powder is weighed and dissolved in 1L of a 1:1 mixture of ethanol and water, and the surfactant alkyl glucoside is added to prepare a 1mol / L ZnCl2 solution. 100g of NH4VO3 is weighed and dispersed in 1L of the 1mol / L ZnCl2 solution. The NH4VO3 is ultrasonically dispersed for 1 hour to ensure uniform dispersion, forming a suspension. The suspension is then placed on a magnetic stirrer and stirred for 30 days. After stirring for the specified time, the suspension is centrifuged, and the precipitate is collected. The precipitate is then dried to obtain zinc ion pre-intercalated hydrated vanadium pentoxide (Zn). 0.2 (V₂O₅·nH₂O), the x value was obtained by inductively coupled plasma analyzer. Zn 0.2 Scanning electron microscopy image of V2O5·nH2O in Figure 4 As given in j), electron microscopy results show that the precursor vanadium-based material successfully self-transformed into fibrous zinc ion pre-intercalated hydrated vanadium pentoxide material.

[0044] Electrode sheets were prepared according to a mass ratio of active material: conductive agent: binder = 7:2:1. The active material (Zn) prepared in this embodiment was used... 0.2 V2O5·nH2O) and a conductive agent (acetylene black) were ground in an agate mortar, and then polyvinylidene fluoride (PVDF) and N-methylpyrrolidone were added and ground into a black paste. The resulting electrode material was placed on a current collector and pressed into an electrode sheet of a certain thickness. The electrode sheet was then vacuum dried at 80 °C for 12 h, and then punched into small round discs with a diameter of 14 mm for later use. The prepared electrode sheet was used as the positive electrode, zinc metal as the negative electrode, 2 mol / L ZnSO4 as the electrolyte, glass fiber as the separator, and stainless steel foil as the current collector. A button cell was assembled, and its constant current charge-discharge performance was tested using a battery performance tester. At a current density of 500 mA / g, Zn 0.2 After 100 cycles of stability testing, the V2O5·nH2O electrode was subjected to Zn 0.2 The discharge specific capacity of the V2O5·nH2O electrode is 376 mA·h / g, and the capacity retention rate is 91.5%.

[0045] Many examples can be listed above. The applicant’s extensive experimental data proves that as long as it is within the scope of the technical solution of this invention, it can be successfully prepared.

Claims

1. A method for preparing fibrous zinc ion pre-intercalated hydrated vanadium pentoxide, characterized in that, The zinc ion pre-intercalated hydrated vanadium pentoxide is fibrous; the chemical composition of the zinc ion pre-intercalated hydrated vanadium pentoxide is ZnxV2O5·nH2O, where x is 0.001~0.5 and n is 0.1~3; The preparation method includes the following steps: First, the vanadium-based compound is dispersed in an aqueous solution or a mixed solution of water and ethanol containing zinc ions and a surfactant; then, the above solution is stirred and reacted for a period of time at a certain temperature; after filtration, washing, and drying, fibrous zinc ion pre-intercalated hydrated vanadium pentoxide is obtained. The vanadium-based compounds include vanadium oxides or vanadate compounds; The zinc ions are derived from zinc salts that are soluble in the aqueous solution or mixed solution, wherein the concentration of the zinc salts in the solution is 0.01 mol / L to 4 mol / L; The concentration of the surfactant in the solution is greater than 0 g / L and less than 10 g / L; The stirring temperature is -5℃ to 100℃; the stirring time is 1 day to 100 days.

2. The preparation method according to claim 1, characterized in that, The vanadium-based compounds include one or more of vanadium monoxide, vanadium trioxide, vanadium dioxide, vanadium pentoxide, vanadium trioxide, vanadium tridecyloxide, orthovanadate MVO4, pyrovanadate MV2O7, and metavanadate MVO3, wherein M is an ammonium ion, sodium ion, potassium ion, iron ion, calcium ion, or bismuth ion.

3. The preparation method according to claim 1, characterized in that, The zinc salt includes one or more of zinc chloride, zinc sulfate, zinc nitrate, zinc chlorate, zinc fluoroborate, zinc fluorosilicate, zinc acetate, and zinc gluconate.

4. The preparation method according to claim 1, characterized in that, The surfactant is one or more of stearic acid, sodium dodecylbenzenesulfonate, sodium dodecyl sulfate, polyvinylpyrrolidone, alkyl glucoside, fatty acid glycerides, fatty acid sorbitan, and polysorbate.

5. The preparation method according to claim 1, characterized in that, The volume ratio of ethanol to water in the mixed solution of ethanol and water is 0.01-2.

6. The preparation method according to claim 1, characterized in that, The drying method is one of vacuum drying, forced air drying, freeze drying, spray drying, and fluidized bed drying.

7. The fibrous zinc ion pre-intercalated hydrated vanadium pentoxide prepared by the preparation method according to any one of claims 1 to 6, characterized in that, The fibrous zinc ion pre-intercalated hydrated vanadium pentoxide has a length of 100 nm–50 μm and a width of 20 nm–500 nm.

8. The application of the fibrous zinc ion pre-intercalated hydrated vanadium pentoxide material according to claim 7, characterized in that, The application of the fibrous zinc ion pre-intercalated hydrated vanadium pentoxide as a cathode material for rechargeable zinc-ion batteries.

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