Metal-ion intercalated nano vanadium-based compound-graphene modified separator and method of making same

Abstract

The application discloses a metal ion embedded nanometer vanadium-based compound-graphene modified diaphragm and a preparation method thereof. The metal ion embedded nanometer vanadium-based compound and graphene are uniformly attached to the battery diaphragm by a suction filtration method, so that the metal ion embedded nanometer vanadium-based compound-graphene modified diaphragm is obtained. The synergistic effect of the nanometer vanadium-based compound and the graphene can effectively inhibit the shuttle effect of polysulfides, accelerate the redox kinetics process and improve the utilization rate of active substances. Therefore, the lithium-sulfur battery prepared by using the diaphragm exhibits excellent discharge specific capacity, good cycle stability and excellent rate performance.

Description

TECHNICAL FIELD

[0001] The present application relates to a metal ion intercalated nanometer vanadium-based compound-graphene modified diaphragm and a preparation method thereof, and belongs to the field of functional materials. BACKGROUND

[0002] Elemental sulfur has the advantages of high theoretical specific capacity (1675 mAh / g), low price, abundant reserves, and relatively environmentally friendly, so lithium-sulfur batteries have become a hot spot in the field of high specific energy batteries. However, there are still many problems in the commercial application of lithium-sulfur batteries: for example, 1) elemental sulfur is an insulator of electrons and ions at room temperature, and the insulating nature of elemental sulfur leads to low utilization rate of sulfur active material and poor rate performance; 2) During charging and discharging, lithium polysulfides are generated inside the battery, which are soluble in electrolyte, forming the so-called "shuttle effect". The "shuttle effect" leads to irreversible loss of sulfur active material, poor electrochemical reversibility, and rapid capacity decay, thereby shortening the cycle life of the battery. Therefore, designing and preparing materials with the performance of promoting charge transfer, inhibiting the shuttle effect, and accelerating the catalytic conversion of polysulfides is crucial for promoting the practical application of lithium-sulfur batteries.

[0003] The diaphragm not only provides a lithium ion diffusion path in the lithium-sulfur battery, but also physically separates the positive and negative plates to prevent short circuits, and can also adjust the transmission behavior of lithium ions. Using a modified battery diaphragm to improve the performance of lithium-sulfur batteries is a good strategy. The modified battery diaphragm not only hinders the shuttle of polysulfides, but also accelerates the conversion of polysulfides. In addition, it can also improve the wettability and thermal stability of the diaphragm to some extent. In recent years, people have carried out research on the above application bottlenecks of lithium-sulfur batteries and have made some progress. A lot of work has also been done on improving the performance of lithium batteries by modifying the diaphragm. Therefore, the modification of diaphragm materials can effectively improve the electrochemical performance of lithium-sulfur batteries and provide support for the industrial application of lithium-sulfur batteries.

[0004] Vanadium has multiple oxidation states, and vanadium-based materials have an open crystal structure, which makes vanadium-based materials exhibit excellent electrochemical performance and have wide prospects in energy storage materials and catalytic materials. For example, transition metal nitride vanadium nitride (VN) is a potential electrode material that has attracted increasing attention due to its high conductivity, pseudo-capacitance, high density, and platinum-like catalytic performance. Therefore, the present application uses vanadium-based compounds to modify the diaphragm. Through the strong adsorption and catalytic ability of nanometer vanadium-based compounds and the high conductivity of graphene, the two work together to effectively inhibit the shuttle effect of polysulfides, accelerate the redox kinetics process, and improve the utilization rate of active materials, which is expected to significantly improve the electrochemical performance of lithium-sulfur batteries. SUMMARY

[0005] The purpose of the present application is to solve the inherent defects of lithium-sulfur batteries, and the present application provides a metal ion embedded nano vanadium-based compound-graphene modified separator and a preparation method thereof.

[0006] The technical solutions of the present application are as follows:

[0007] A metal ion embedded nano vanadium-based compound-graphene modified separator, wherein the metal ion embedded nano vanadium-based compound and graphene are uniformly attached to the battery separator by the method of suction filtration, so as to obtain the metal ion embedded nano vanadium-based compound-graphene modified separator.

[0008] Specifically, the metal ion embedded nano vanadium-based compound includes one or more of metal ion embedded nano vanadium dioxide, metal ion embedded nano vanadium nitride, metal ion embedded nano vanadium sulfide, metal ion embedded nano vanadium carbide, surface-nitrided metal ion embedded nano vanadium oxide, and surface-sulfurized metal ion embedded nano vanadium oxide.

[0009] A preparation method of a metal ion embedded nano vanadium-based compound-graphene modified separator, wherein the nano vanadium-based compound and graphene are uniformly attached to the battery separator by the method of coating, suction filtration or spraying, so as to obtain the nano vanadium-based compound-graphene modified separator.

[0010] Further preferably, the nano vanadium-based compound is metal ion embedded nano vanadium dioxide, and the preparation process is as follows: adding vanadium pentoxide into a metal salt solution, stirring for 72-144 hours, centrifuging and washing to obtain a precursor, then adding the precursor into a water and organic mixed solution, the volume ratio of the water and the organic liquid being between 1:2 and 1:10, placing the solution in a reaction kettle for heating, the heating temperature being 140-200 DEG C, and the heating time being 6-36 hours, and then centrifuging and washing to obtain the metal ion embedded nano vanadium dioxide.

[0011] Further preferably, the nano vanadium-based compound is a product of further processing of the metal ion embedded nano vanadium dioxide, and the metal ion embedded nano vanadium dioxide is heated in a tube furnace under the condition of adding a nitrogen source, a sulfur source and a carbon source, the heating temperature being 500-800 DEG C, and the heating time being 0.1-4 hours, so as to obtain the metal ion embedded nano vanadium nitride, the metal ion embedded nano vanadium sulfide, the metal ion embedded nano vanadium carbide, the surface-nitrided metal ion embedded nano vanadium oxide or the surface-sulfurized metal ion embedded nano vanadium oxide.

[0012] Specifically, the nitrogen source includes ammonia, urea and melamine, the sulfur source includes hydrogen sulfide, thiourea and sulfur, and the carbon source includes carbon powder, glucose and sucrose.

[0013] Specifically, the metal salt is one, two, three or more of sodium chloride, lithium chloride, zinc chloride, potassium chloride, calcium chloride, magnesium chloride, cobalt chloride, nickel chloride, iron chloride, copper chloride.

[0014] Specifically, the organic liquid is one, two or more of ethanol, ethylene glycol, polyethylene glycol 200, polyethylene glycol 400, polyethylene glycol 600.

[0015] The metal ion-embedded nanometer vanadium-based compound-graphene modified separator synthesized by the application can effectively inhibit the shuttle effect of polysulfides, accelerate the redox kinetics process and improve the utilization rate of active substances by virtue of the strong adsorption and catalytic capacity of one-dimensional nanometer vanadium-based compounds and the high conductivity of graphene.

[0016] The metal ion-embedded one-dimensional nanometer vanadium-based compound-graphene modified separator according to the application has simple preparation process, safe reaction condition, simple operation and little harm to the environment, and can be suitable for large-scale production. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 X-ray diffraction pattern of the metal zinc ion-embedded nanometer vanadium dioxide prepared in Example 1;

[0018] Figure 2 Scanning electron microscope pattern of the metal zinc ion-embedded nanometer vanadium dioxide material prepared in Example 1;

[0019] Figure 3 Cross-sectional view of the metal zinc ion-embedded nanometer vanadium dioxide-graphene modified separator prepared in Example 1;

[0020] Figure 4 Zn, V and O element surface distribution map of the cross section of the metal zinc ion-embedded nanometer vanadium dioxide-graphene modified separator prepared in Example 1;

[0021] Figure 5 Photo of the metal zinc ion-embedded nanometer vanadium dioxide-graphene modified separator prepared in Example 1;

[0022] Figure 6 Discharge test results of the battery using the material prepared in Example 1 at different current densities of 167.5 mA / g, 335 mA / g, 837.5 mA / g, 1675 mAh / g and 3350 mA / g;

[0023] Figure 7 Cycle life curve comparison diagram of the battery using the material prepared in Example 2 at a current density of 1675 mAh / g;

[0024] Figure 8 The discharge test results of the battery prepared in Example 3 at different current densities of 1675 mAh / g and the like. DETAILED DESCRIPTION

[0025] In order to make the above objectives, characteristics and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0026] The present application provides a preparation method of a metal ion embedded nano vanadium-based compound-graphene modified separator, and the nano vanadium-based compound and graphene are uniformly attached to the battery separator by coating, suction filtration or spraying method, so as to obtain a nano vanadium-based compound-graphene modified separator.

[0027] The nano vanadium-based compound is metal ion embedded nano vanadium dioxide, and the preparation process is as follows: vanadium pentoxide is added into a metal salt solution, stirring for 72-144 hours, centrifugation and washing to obtain a precursor, then the precursor is added into a water and organic mixed solution, the volume ratio of the water and the organic liquid is between 1:2 and 1:10, and the mixed solution is placed in a reaction kettle for heating, the heating temperature is 140-200℃, and the heating time is 6-36 hours, and then centrifugation and washing are performed to obtain the metal ion embedded nano vanadium dioxide. The metal salt is one, two, three or more of sodium chloride, lithium chloride, zinc chloride, potassium chloride, calcium chloride, magnesium chloride, cobalt chloride, nickel chloride, iron chloride, copper chloride. The organic liquid is one, two or more of ethanol, ethylene glycol, polyethylene glycol 200, polyethylene glycol 400 and polyethylene glycol 600.

[0028] The nano vanadium-based compound is a product further treated from the metal ion embedded nano vanadium dioxide, and the metal ion embedded nano vanadium dioxide is heated in a tube furnace, and under the conditions of adding a nitrogen source, a sulfur source and a carbon source, the heating temperature is 500-800℃, and the heating time is 0.1-4 hours, so as to obtain metal ion embedded nano vanadium nitride, metal ion embedded nano vanadium sulfide, metal ion embedded nano vanadium carbide, surface-nitrided metal ion embedded nano vanadium oxide or surface-sulfurized metal ion embedded nano vanadium oxide. The nitrogen source includes ammonia, urea and melamine; the sulfur source includes hydrogen sulfide, thiourea and sulfur; and the carbon source includes carbon powder, glucose and sucrose.

[0029] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. Example 1

[0030] Metal zinc ion-embedded nanometer vanadium dioxide-graphene modified separator and preparation method thereof

[0031] (1) First, vanadium pentoxide is added to a zinc chloride solution, stirred for 96 hours, centrifuged and washed to obtain a zinc ion-embedded vanadium pentoxide precursor.

[0032] (2) The prepared zinc ion-embedded vanadium pentoxide precursor is added to a mixture of water and ethylene glycol, the volume ratio of water to ethylene glycol is between 2:1, heated in a reaction kettle, the heating temperature is 180℃, the heating time is 12 hours, centrifuged and washed to obtain zinc ion-embedded nanometer vanadium dioxide. Figure 1 is the X-ray diffraction pattern of zinc ion-embedded vanadium dioxide, Figure 2 is the scanning electron microscope image of zinc ion-embedded vanadium dioxide. As Figure 2 shown, zinc ion-embedded vanadium dioxide presents as nanorods and nanowires, with a length distribution of 1 to 3 microns and a diameter of 10 to 80 nanometers.

[0033] (3) Modification of the separator: zinc ion-embedded nanometer vanadium dioxide and graphene are dispersed in ethanol solvent at a mass fraction of 9:1, ultrasonic stirring is performed to obtain a dispersion liquid. The zinc ion-embedded nanometer vanadium dioxide-graphene dispersion liquid is uniformly attached to the battery separator by suction filtration, thereby obtaining a zinc ion-embedded nanometer vanadium dioxide-graphene modified separator. Figure 3 is the cross-sectional view of zinc ion-embedded vanadium dioxide, Figure 4 is the surface Zn, V, O element distribution map of the metal zinc ion-embedded vanadium dioxide-graphene modified separator, Figure 5 is the photo of the metal zinc ion-embedded vanadium dioxide-graphene modified separator. As Figure 3 shown, the vanadium dioxide and graphene on the surface of the separator are uniformly distributed, and the thickness of the modified layer of the cross section of the separator is between 40 and 50 microns. As Figure 4 shown, the Zn, V, O elements of the modified layer of the cross section of the separator are uniformly distributed.

[0034] (4) The zinc ion intercalated nano vanadium dioxide-graphene modified separator prepared above, metal lithium as the negative electrode, carbon-sulfur positive electrode, electrolyte is an additive of 0.1 mol / L anhydrous lithium nitrate, solvent is a mixed solution of 1,3 dioxolane and ethylene glycol dimethyl ether prepared according to the volume ratio of 1:1, 1.0 mol / L lithium bis(trifluoromethylsulfonyl) imide solution, assembled into a lithium-sulfur battery in a glove box. The carbon-sulfur positive electrode is obtained by mixing and grinding carbon bp2000 and elemental sulfur at a ratio of 2:8, and then heating at 155°C for 12 hours. The charge-discharge cycle life test results at current densities of 167.5 mA / g, 335 mA / g, 837.5 mA / g, 1675 mA / g, 3350 mA / g, etc. are shown in Table 2. Figure 6 As a comparison, a battery using an unmodified separator is assembled according to the above steps. At 167.5 mA / g, the first cycle discharge capacity of the battery electrode using the PP separator is 1032.6 mAh / g, while the highest discharge capacity of the battery electrode using the zinc ion intercalated nano vanadium dioxide-graphene modified separator is 1468.5 mAh / g, and the highest discharge capacity of the battery using the zinc ion intercalated nano vanadium dioxide-graphene modified separator is 1.42 times that of the battery electrode using the PP separator. At 167.5 mA / g, the first cycle discharge capacity of the battery electrode using the zinc ion intercalated nano vanadium dioxide modified separator is 1313.2 mAh / g, while the highest discharge capacity of the battery electrode using the zinc ion intercalated nano vanadium dioxide-graphene modified separator is 1468.5 mAh / g, and the highest discharge capacity of the battery using the zinc ion intercalated nano vanadium dioxide-graphene modified separator is 1.25 times that of the battery electrode using the zinc ion intercalated nano vanadium dioxide modified separator. At 167.5 mA / g, the first cycle discharge capacity of the battery electrode using the graphene modified separator is 1169.8 mAh / g, while the highest discharge capacity of the battery electrode using the zinc ion intercalated nano vanadium dioxide-graphene modified separator is 1468.5 mAh / g, and the highest discharge capacity of the battery using the zinc ion intercalated nano vanadium dioxide-graphene modified separator is 1.12 times that of the battery electrode using the graphene modified separator.

[0035] The first cycle discharge capacity of the battery electrode using PP separator was 395.2 mAh / g at 3350 mA / g, while the highest discharge capacity of the battery electrode using zinc ion-embedded nano vanadium dioxide-graphene modified separator was 868.4 mAh / g, and the highest discharge capacity of the battery using zinc ion-embedded nano vanadium dioxide-graphene modified separator was 2.2 times that of the battery electrode using PP separator. The first cycle discharge capacity of the battery electrode using zinc ion-embedded nano vanadium dioxide modified separator was 358.3 mAh / g at 3350 mA / g, while the highest discharge capacity of the battery electrode using zinc ion-embedded nano vanadium dioxide-graphene modified separator was 868.4 mAh / g, and the highest discharge capacity of the battery using zinc ion-embedded nano vanadium dioxide-graphene modified separator was 2.42 times that of the battery electrode using zinc ion-embedded vanadium dioxide modified separator. The first cycle discharge capacity of the battery electrode using graphene modified separator was 584.7 mAh / g at 3350 mA / g, while the highest discharge capacity of the battery electrode using zinc ion-embedded nano vanadium dioxide-graphene modified separator was 868.4 mAh / g, and the highest discharge capacity of the battery using zinc ion-embedded vanadium dioxide-graphene modified separator was 1.48 times that of the battery electrode using graphene modified separator. Example 2

[0036] Metallic zinc-sodium dual ion-embedded vanadium oxide-graphene modified separator and a preparation method thereof

[0037] (1) First, vanadium pentoxide was added to a zinc chloride solution, and stirred for 96 hours, centrifuged and washed to obtain a zinc ion-embedded vanadium pentoxide precursor. Then, the zinc ion-embedded vanadium pentoxide precursor was added to a sodium chloride solution, and stirred for 72 hours, centrifuged and washed to obtain a metallic zinc-sodium dual ion-embedded vanadium pentoxide precursor.

[0038] (2) The prepared metallic zinc-sodium dual ion-embedded vanadium pentoxide precursor was added to a mixture of water and ethylene glycol, and the volume ratio of water to ethylene glycol was between 1:2, and was placed in a reaction kettle for heating, the heating temperature was 180°C, and the heating time was 12 hours, and then centrifuged and washed to obtain a metallic zinc-sodium dual ion-embedded vanadium oxide.

[0039] (3) Modification of the separator: the metallic zinc-sodium dual ion-embedded vanadium oxide and graphene were dispersed in ethanol solvent at a mass fraction of 9:1 under ultrasonic and stirring to obtain a dispersion liquid. Then, the metallic zinc-sodium dual ion-embedded vanadium oxide-graphene dispersion liquid was uniformly attached to the battery separator by suction filtration, thereby obtaining a metallic zinc-sodium dual ion-embedded vanadium oxide-graphene modified separator.

[0040] (4) The metal zinc-sodium dual ion intercalated vanadium oxide-graphene modified separator prepared above, metal lithium as the negative electrode, carbon-sulfur positive electrode, electrolyte is anhydrous lithium nitrate solution with 0.1 mol / L of additive and solvent is a mixed solution of 1, 3 dioxolane and ethylene glycol dimethyl ether prepared according to the volume ratio of 1:1, 1.0 mol / L of lithium bis(trifluoromethylsulfonyl) imide solution, and assembled into a lithium-sulfur battery in a glove box. The carbon-sulfur positive electrode is obtained by mixing and grinding carbon bp2000 and elemental sulfur at a ratio of 2:8, and then heating at 155°C for 12 hours. The charge-discharge cycle life test results at 1675 mAh / g are shown in Table 1. As a comparison, a battery using an unmodified separator is assembled according to the above steps. At 1675 mA / g, the first cycle discharge capacity of the battery electrode using the PP separator is 279.0 mAh / g, while the highest discharge capacity of the battery electrode using the metal zinc-sodium dual ion intercalated vanadium oxide-graphene modified separator is 1088.7 mAh / g, and the highest discharge capacity of the battery using the metal zinc-sodium dual ion intercalated vanadium oxide-graphene modified separator is 3.9 times that of the battery electrode using the PP separator. After 300 cycles at 1675 mA / g, the first cycle discharge capacity of the battery electrode using the PP separator is 461.8 mAh / g, while the highest discharge capacity of the battery electrode using the metal zinc-sodium dual ion intercalated vanadium oxide-graphene modified separator is 581.0 mAh / g, and the highest discharge capacity of the battery using the metal zinc-sodium dual ion intercalated vanadium oxide-graphene modified separator is 1.25 times that of the battery electrode using the PP separator. Figure 7 As shown in Table 1. As a comparison, a battery using an unmodified separator is assembled according to the above steps. At 1675 mA / g, the first cycle discharge capacity of the battery electrode using the PP separator is 279.0 mAh / g, while the highest discharge capacity of the battery electrode using the metal zinc-sodium dual ion intercalated vanadium oxide-graphene modified separator is 1088.7 mAh / g, and the highest discharge capacity of the battery using the metal zinc-sodium dual ion intercalated vanadium oxide-graphene modified separator is 3.9 times that of the battery electrode using the PP separator. After 300 cycles at 1675 mA / g, the first cycle discharge capacity of the battery electrode using the PP separator is 461.8 mAh / g, while the highest discharge capacity of the battery electrode using the metal zinc-sodium dual ion intercalated vanadium oxide-graphene modified separator is 581.0 mAh / g, and the highest discharge capacity of the battery using the metal zinc-sodium dual ion intercalated vanadium oxide-graphene modified separator is 1.25 times that of the battery electrode using the PP separator. Example 3

[0041] Metal zinc ion intercalated vanadium nitride-graphene modified separator and its preparation method:

[0042] (1) First, add vanadium pentoxide to a zinc chloride solution, stir for 96 hours, centrifuge, wash, and freeze-dry to obtain a zinc ion intercalated vanadium pentoxide precursor.

[0043] (2) Add the prepared zinc ion intercalated vanadium pentoxide precursor to a mixture of water and ethylene glycol, with a volume ratio of water to ethylene glycol between 2:1, heat in a reaction kettle, heating temperature is 180°C, heating time is 12 hours, centrifuge, wash, to obtain zinc ion intercalated nano vanadium dioxide.

[0044] (3) The prepared zinc ion intercalated vanadium dioxide precursor is heated under the condition of adding ammonia gas, the heating temperature is 600°C, and the heating time is 1 hour, to obtain metal zinc ion intercalated vanadium nitride.

[0045] (4) Modification of the diaphragm: zinc ion-embedded vanadium nitride, graphene was dispersed in ethanol solvent according to the mass fraction of 9:1, ultrasonic stirring, to obtain a dispersion liquid. Then the metal zinc ion-embedded vanadium nitride-graphene dispersion liquid was uniformly attached to the battery diaphragm by suction filtration method, thereby obtaining the zinc ion-embedded vanadium nitride modified diaphragm.

[0046] (5) The zinc ion-embedded vanadium nitride-graphene modified diaphragm prepared above, metal lithium as the negative electrode, carbon-sulfur positive electrode, electrolyte is an additive of 0.1 mol / L anhydrous lithium nitrate, solvent is a mixed solution prepared according to the volume ratio of 1:1 of 1,3-dioxolane and ethylene glycol dimethyl ether, 1.0 mol / L lithium bis(trifluoromethyl sulfonyl) imide solution, assembled into a lithium-sulfur battery in a glove box. The carbon-sulfur positive electrode is a mixture of carbon bp2000 and elemental sulfur in a ratio of 2:8, which is ground and heated at 155°C for 12 hours. The charge-discharge cycle life test results are shown in Figure 8

[0047] Finally, it should be noted that: the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor belong to the scope of protection of the present application.​

Claims

1. A method for preparing a metal ion-intercalated one-dimensional nano-vanadium-based compound-graphene modified membrane, characterized in that, One-dimensional vanadium nano-based compounds and graphene with metal ions embedded are uniformly attached to the battery separator by coating, filtration or spraying methods, thereby obtaining a separator modified with one-dimensional vanadium nano-based compounds with metal ions embedded in graphene. The preparation process of the one-dimensional nano-vanadium-based compound with metal ion intercalation is as follows: vanadium pentoxide is added to a metal salt solution and stirred for 72-144 hours. After centrifugation and washing, a precursor is obtained. Then, the precursor is added to a mixture of water and organic liquid. The metal salt is one or more of sodium chloride, lithium chloride, zinc chloride, potassium chloride, calcium chloride, magnesium chloride, cobalt chloride, nickel chloride, ferric chloride, and copper chloride. The volume ratio of water to organic liquid is between 1:2 and 1:

10. The mixture is placed in a reaction vessel and heated at 140-200℃ for 6-36 hours. After centrifugation and washing, nano-vanadium dioxide with metal ion intercalation is obtained.

2. The method for preparing a one-dimensional nano-vanadium-based compound-graphene-modified membrane with metal ion intercalation according to claim 1, characterized in that, The metal ion-intercalated one-dimensional nano-vanadium-based compound is a product of further processing of metal ion-intercalated nano-vanadium dioxide. The metal ion-intercalated nano-vanadium dioxide is placed in a tube furnace and heated at 500-800°C for 0.1-4 hours with the addition of a nitrogen source, sulfur source, or carbon source, to obtain metal ion-intercalated nano-vanadium nitride, metal ion-intercalated nano-vanadium sulfide, metal ion-intercalated nano-vanadium carbide, surface-nitrided metal ion-intercalated nano-vanadium oxide, or surface-sulfrided metal ion-intercalated nano-vanadium oxide.

3. The method for preparing a one-dimensional nano-vanadium-based compound-graphene-modified membrane with metal ion intercalation according to claim 2, characterized in that, The nitrogen source is ammonia, urea, or melamine; the sulfur source is hydrogen sulfide, thiourea, or sulfur; and the carbon source is toner, glucose, or sucrose.

4. The method for preparing a one-dimensional nano-vanadium-based compound-graphene-modified membrane with metal ion intercalation according to claim 1, characterized in that, The organic liquid is one or more of ethanol, ethylene glycol, polyethylene glycol 200, polyethylene glycol 400, and polyethylene glycol 600.

5. A metal ion-intercalated one-dimensional nano-vanadium-based compound-graphene-modified membrane, characterized in that, The diaphragm is prepared according to the preparation method described in any one of claims 1-4.

Images