A one-dimensional 2H phase MoS 1.5 X 0.5 Nanowire material, method of making, use and battery

Abstract

The present invention discloses a one-dimensional 2H phase MoS 1.5 X 0.5 Nanowire material, preparation method, application and battery thereof. The preparation method comprises: placing a mixture containing Mo2S3 nanowires and X element in a reaction tube, evacuating and sealing the reaction tube, and calcining at 350-1000°C for 2-20 hours to obtain the one-dimensional 2H phase MoS 1.5 X 0.5 Nanowire material; wherein X is one or more of S, Se and Te. The preparation method of the present invention is simple, the reaction source is environmentally friendly, and it is easy to industrialize. The prepared one-dimensional 2H phase MoS 1.5 X 0.5 The nanowire material has uniform morphology and high single crystallinity, and has excellent electrochemical properties when used in sodium ion batteries.

Description

TECHNICAL FIELD

[0001] The present application relates to a one-dimensional 2H phase MoS 1.5 X 0.5 Nanowire material, preparation method, application and battery thereof. BACKGROUND

[0002] In recent years, one-dimensional nanomaterials are the research focus in the field of nanomaterials, and are one of the material foundations of future high technologies. One-dimensional nanomaterials are widely used in electronic devices, photonic devices, photoelectrochemistry and energy storage and conversion fields due to their unique size effect and tunable electronic and optical properties. Layered transition metal chalcogenides are a typical low-dimensional material, which has rich chemical composition and physical properties. Among them, one-dimensional MoS2 nanomaterials have high ionic conductivity and electronic conductivity, and have great potential for energy storage applications. However, due to the high symmetry space group P63 / mmc of MoS2, it exhibits isotropy in the MoS2 plane, which makes it tend to grow into a triangular or hexagonal sheet rather than a one-dimensional wire during growth. The common preparation methods of one-dimensional MoS2 nanomaterials at present mainly include the top-down strategy represented by chemical exfoliation and the bottom-up strategy represented by chemical vapor deposition. However, they often have the problems of complex preparation and difficulty in large-scale preparation, so the controllable preparation of one-dimensional layered transition metal chalcogenide nanowires is a great challenge due to the limitation of crystal structure. SUMMARY

[0003] The technical problem solved by the present application is to overcome the defects of the prior art that the preparation method of one-dimensional layered transition metal chalcogenide nanowires is complex and difficult to prepare on a large scale, and to provide a one-dimensional 2H phase MoS 1.5 X 0.5 Nanowire material, preparation method, application and battery thereof. The preparation method of the present application is simple, the reaction source is friendly to the environment, and the industrial production is easy. The one-dimensional 2H phase MoS 1.5 X 0.5 Nanowire material prepared by the present application has uniform morphology and high single crystal, and has excellent electrochemical performance when applied to sodium ion batteries.

[0004] In the present application, Mo2S3 nanowires and elemental X (X=S, Se, Te) are subjected to a sulfidation reaction by a solid-phase synthesis method, so as to prepare 2H phase MoS 1.5 X 0.5 Nanowires. During the reaction, the elemental X is converted into a gaseous state at high temperature and reacts with the Mo2S3 nanowires, so as to convert them into 2H phase MoS 1.5 X 0.5 Nanowires.

[0005] The application solves the above technical problems through the following technical solutions

[0006] The application provides a one-dimensional 2H phase MoS 1.5 X 0.5 A preparation method of nanowire material, comprising the following steps:

[0007] The mixture containing Mo2S3 nanowires and X element is placed in a reaction tube, the reaction tube is vacuumized and sealed, and then calcination is carried out at 350-1000 ℃ for 2-20 h to obtain the one-dimensional 2H phase MoS 1.5 X 0.5 Nanowire material; wherein X is one or more of S, Se and Te.

[0008] In the application, the molar ratio of the X element to the Mo2S3 nanowires is preferably not less than 1, more preferably 1-1.2, for example 1 or 1.1. When the amount of the X element is too small, Mo2S3 cannot be completely converted, and thus MoS 1.5 X 0.5 Nanowires cannot be obtained.

[0009] In the application, the preparation method of the mixture containing Mo2S3 nanowires and X element can be conventional in the art, for example, the Mo2S3 nanowires and the X element are uniformly ground to obtain the mixture. The grinding is generally carried out in an air atmosphere.

[0010] In the application, the reaction tube is preferably a quartz tube.

[0011] In the application, after the vacuumization, the vacuum degree of the reaction tube is preferably less than or equal to 10 -3 Pa.

[0012] In the application, according to the conventional practice in the art, the reaction tube can be sealed by a quartz column to realize sealing after the vacuumization.

[0013] In the application, the calcination is generally carried out in a muffle furnace.

[0014] In the application, the rate of temperature rise to the calcination temperature can be 120-300 ℃ / h, for example 160 ℃ / h.

[0015] In the application, the calcination temperature is preferably 500-900 ℃, for example 500 ℃, 600 ℃ or 700 ℃.

[0016] In the application, the calcination time is preferably 3-12 h, for example 3 h, 5 h or 10 h.

[0017] In certain embodiments, when the X is Se and / or Te, the temperature of the calcination is 600-750℃, and the time of the calcination is 3-12h.

[0018] In certain embodiments, when the X is Te, the temperature of the calcination is 600-750℃, and the time of the calcination is 8-12h.

[0019] In the present application, during the calcination, generally the end of the reaction tube with the mixed powder is placed in a preset temperature zone, and is kept at a preset temperature for a preset time.

[0020] In the present application, according to the conventional practice in the art, after the calcination, generally natural cooling to room temperature is needed.

[0021] In the present application, the diameter of the Mo2S3 nanowire can be 100-600nm. The length of the Mo2S3 nanowire can be 50-200μm.

[0022] In the present application, the Mo2S3 nanowire can be obtained from conventional commercial sources or prepared according to the conventional practice in the art, for example, prepared according to the solid phase synthesis method.

[0023] In the present application, the preparation method of the Mo2S3 nanowire preferably comprises the following steps: placing a mixture of molybdenum powder, sulfur powder, red phosphorus and sodium chloride in a quartz tube, vacuumizing and sealing the quartz tube, and then calcining at 750-1200℃ for 20-48h, and then washing and drying.

[0024] In the present application, the molar ratio of the molybdenum powder and the sulfur powder is generally stoichiometric, for example, 2:3.

[0025] In the present application, the mass of the red phosphorus is preferably 2%-10% of the sum of the mass of the molybdenum powder and the sulfur powder, preferably 3%-8%, for example, 5%.

[0026] In the present application, the mass of the sodium chloride is preferably 3-8 times, for example, 5 times, of the sum of the mass of the molybdenum powder and the sulfur powder.

[0027] In the present application, the preparation method of the mixture can be conventional in the art, for example, grinding the molybdenum powder, the sulfur powder, the red phosphorus and the sodium chloride uniformly, or first mixing the molybdenum powder and the sulfur powder, and then adding the red phosphorus and the sodium chloride for grinding.

[0028] In the present application, the calcination is generally carried out in a muffle furnace. The temperature of the calcination is preferably 800-1100℃, for example, 950℃. The time of the calcination is preferably 24-48h, for example, 33.3h.

[0029] The solvent used in the washing can be conventional in the art, such as deionized water. The drying can be conventional in the art, such as oven drying. The drying temperature can be 80-120℃, such as 100℃. The drying time can be 6-24h, such as 12h.

[0030] The application also provides a one-dimensional 2H phase MoS 1.5 X 0.5 nanowire material.

[0031] The application also provides a one-dimensional 2H phase MoS 1.5 X 0.5 nanowire material, X being one or more of S, Se and Te, the MoS 1.5 X 0.5 nanowire having a diameter of 100-800nm and a length of 50-200μm.

[0032] In the application, the one-dimensional 2H phase MoS 1.5 X 0.5 nanowire material preferably has a diameter of 200-400nm, such as 200nm, 300nm or 400nm.

[0033] In the application, the one-dimensional 2H phase MoS 1.5 X 0.5 nanowire material preferably has a length of 100-150μm, such as 100μm, 120μm or 150μm.

[0034] The application also provides a one-dimensional 2H phase MoS 1.5 X 0.5 nanowire material for use in a sodium ion battery.

[0035] The application also provides a sodium ion battery comprising a one-dimensional 2H phase MoS 1.5 X 0.5 nanowire material.

[0036] In the sodium ion battery, the one-dimensional 2H phase MoS 1.5 X 0.5 nanowire material is preferably used as a negative electrode material.

[0037] On the basis of common general knowledge in the art, the above preferred conditions can be combined in any manner, to obtain preferred embodiments of the application.

[0038] The reagents and raw materials used in the application are commercially available.

[0039] The positive progress of the application is that:

[0040] The application first adopts in-situ topological phase transition reaction of Mo2S3 nanowires to successfully prepare one-dimensional 2H phase structure MoS 1.5 X 0.5 nanowires, which makes up for the defects of MoS 1.5 X 0.5 nanowires, and the preparation method provided by the application has simple steps, short growth cycle, high success rate (about 100%), and the obtained MoS 1.5 X 0.5 nanowires have large quantity, high length-diameter ratio, uniform morphology and high crystallinity. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 The structure of the quartz tube and the placement position of raw materials in the quartz tube in the embodiment of the application;

[0042] Figure 2 An optical photo of the 2H phase MoS2 nanowires prepared in Example 1;

[0043] Figure 3 A scanning electron microscope (SEM) photo of the 2H phase MoS2 nanowires prepared in Example 1;

[0044] Figure 4 An X-ray diffraction (XRD) photo of the 2H phase MoS2 nanowires prepared in Example 1;

[0045] Figure 5 A Raman photo of the 2H phase MoS2 nanowires prepared in Example 1.

[0046] Figure 6 A scanning electron microscope (SEM) photo of the MoS 1.5 Se 0.5 nanowires prepared in Example 2;

[0047] Figure 7 An X-ray diffraction (XRD) photo of the MoS 1.5 Se 0.5 nanowires prepared in Example 2;

[0048] Figure 8 A Raman photo of the MoS 1.5 Se 0.5 nanowires prepared in Example 2;

[0049] Figure 9 A scanning electron microscope (SEM) photo of the MoS 1.5 Te 0.5 nanowires prepared in Example 3;

[0050] Figure 10 An X-ray diffraction (XRD) photo of the MoS 1.5 Te 0.5 nanowires prepared in Example 3;

[0051] Figure 11 XRD pattern of the MoS2nanowires prepared in Example 1; 1.5 Te 0.5 Raman pattern of the nanowires;

[0052] Figure 12 XRD pattern of the nanowires prepared in Comparative Example 1;

[0053] Figure 13 XRD pattern of the nanowires prepared in Comparative Example 2;

[0054] Figure 14 Small current cycling performance pattern of the 2H phase MoS2nanowires prepared in Example 1;

[0055] Figure 15 Rate performance pattern of the 2H phase MoS2nanowires prepared in Example 1;

[0056] Figure 16 Long cycling test pattern of the 2H phase MoS2nanowires prepared in Example 1. DETAILED DESCRIPTION

[0057] The present application is further illustrated by the following examples without limiting the present application to the examples described. The experimental methods in the following examples, if not otherwise specified, are selected according to the conventional methods and conditions, or according to the commercial instruction.

[0058] The preparation method of the Mo2S3nanowires used in the following examples is as follows:

[0059] High purity molybdenum powder (purity of 99.9%) and high purity sulfur powder (purity of 99.99%) are mixed according to a molar ratio of 2:3, and red phosphorus and sodium chloride powder (purity of 99.9%) are added and ground to mix well to obtain a mixed powder, and the mixed powder is placed in a quartz tube; wherein the mass of the red phosphorus is 5% of the sum of the mass of the molybdenum powder and the sulfur powder, and the mass of the sodium chloride powder is 5 times of the sum of the mass of the molybdenum powder and the sulfur powder.

[0060] The quartz tube containing the mixed powder inside is vacuumed and sealed, placed in a muffle furnace, heated to 950°C at a rate of 120°C / h and kept for 2000 minutes, then the heating is stopped, and naturally cooled to room temperature to obtain a product, and the product is washed with water, suction filtered, and dried at 100°C for 12 hours to obtain Mo2S3nanowires. The Mo2S3nanowires prepared have a diameter of 300-500 nm and a length of 50-150 μm.

[0061] Example 1

[0062] (1) Mo2S3 nanowires are mixed with elemental sulfur in air by grinding to obtain a mixed powder, wherein the molar ratio of Mo2S3 nanowires to elemental sulfur is 1:1;

[0063] (2) The mixed powder is placed in one end of a quartz tube, vacuumed to make the air pressure at the tube opening less than 10 -3 Pa, and the tube is sealed; the quartz tube is placed in a muffle furnace, the muffle furnace is heated to 500°C at a rate of 160°C / h and kept for 3 h, then the heating is stopped, the muffle furnace is naturally cooled to room temperature, and the end of the quartz tube with the mixed powder obtains 2H phase MoS2 nanowires with good quality.

[0064] Example 2

[0065] (1) Mo2S3 nanowires are mixed with elemental selenium in air by grinding to obtain a mixed powder, wherein the molar ratio of Mo2S3 nanowires to elemental selenium is 1:1;

[0066] (2) The mixed powder is placed in one end of a quartz tube, vacuumed to make the air pressure at the tube opening less than 10 -3 Pa, and the tube is sealed; the quartz tube is placed in a muffle furnace, the muffle furnace is heated to 700°C at a rate of 160°C / h and kept for 3 h, then the heating is stopped, the muffle furnace is naturally cooled to room temperature, and the end of the quartz tube with the mixed powder obtains MoS 1.5 Se 0.5 nanowires with good quality.

[0067] Example 3

[0068] (1) Mo2S3 nanowires are mixed with elemental tellurium in air by grinding to obtain a mixed powder, wherein the molar ratio of Mo2S3 nanowires to elemental tellurium is 1:1;

[0069] (2) The mixed powder is placed in one end of a quartz tube, vacuumed to make the air pressure at the tube opening less than 10 -3 Pa, and the tube is sealed; the quartz tube is placed in a muffle furnace, the muffle furnace is heated to 700°C at a rate of 160°C / h and kept for 10 h, then the heating is stopped, the muffle furnace is naturally cooled to room temperature, and the end of the quartz tube with the mixed powder obtains MoS 1.5 Te 0.5 nanowires with good quality.

[0070] Comparative Example 1

[0071] Compared with Example 1, except that the calcination temperature in step (2) is adjusted to 300°C, the other parameters and conditions are the same as those in Example 1.

[0072] Comparative Example 2

[0073] Compared with Example 1, except that the holding time in step (2) is adjusted to 1 h, the other parameters and conditions are the same as those in Example 1.

[0074] Effect embodiment

[0075] (1) Morphology and structure characterization

[0076] Figure 1 The structure of the quartz tube in the embodiment of the present invention and the preparation of MoS 1.5 X 0.5 Nanowires are where the reaction raw materials are placed in the quartz tube.

[0077] The physical picture of the 2H phase MoS2 nanowire prepared in Example 1 is as follows Figure 2 As shown in FIG, it appears as gray-black powder clusters; its SEM image is as shown in FIG. Figure 3 As shown in the figure, it can be seen that the length of the 2H phase MoS2 nanowire is about 150μm and the diameter is 400nm; its XRD is as follows Figure 4 As shown, it can be seen that the prepared MoS2 is 2H phase; its Raman diagram is as follows Figure 5 As shown, the typical E 2g and A 1g The peak also proves that MoS2 is 2H phase.

[0078] MoS prepared in Example 2 1.5 Se 0.5 SEM images of nanowires Figure 6 As shown in the figure, it can be seen that MoS 1.5 Se 0.5 The length of the nanowire is about 100 μm and the diameter is 200 nm; its XRD Figure 7 As shown, it can be seen that the prepared material is MoS 1.5 Se 0.5 ; Its Raman diagram is as follows Figure 8 shown.

[0079] MoS prepared in Example 3 1.5 Te 0.5 SEM images of nanowires Figure 9 As shown in the figure, it can be seen that MoS 1.5 Te 0.5 The length of the nanowire is about 100 μm and the diameter is 400 nm; its XRD Figure 10 As shown, it can be seen that the prepared material is MoS 1.5 Te 0.5 ; Its Raman diagram is as follows Figure 11 shown.

[0080] The final product prepared in Comparative Example 1-2 was subjected to XRD test.Figure 12-13 As shown, it can be seen that the prepared product is a mixture of Mo2S3 and 2H phase MoS2, rather than pure 2H phase MoS2. It can be seen that when the calcination temperature is lower than 500°C or the calcination time is lower than 3h, pure 2H phase MoS2 cannot be obtained.

[0081] (2) Electrochemical performance test

[0082] The electrochemical performance of the final product prepared in each of the above examples was evaluated using a CR2032 button cell.

[0083] The final product material prepared in Examples 1-3, SuperP and polyvinylidene fluoride (PVDF) were uniformly mixed at a mass ratio of 8:1:1 to prepare an electrode slurry in NMP solvent. Then the electrode slurry was uniformly coated on a copper foil using a coating machine, and dried at 120°C in a vacuum environment overnight. Finally, anode sheets with a hole diameter of 13mm were punched on a tablet press, and the loading was about 1-2mg cm -2 . The prepared electrode was used as the negative electrode, pure sodium was used as the counter electrode, GF / D glass fiber was used as the separator, and the organic electrolyte was 1.0M NaPF6 in DEGDME = 100Vol%. A CR2032 coin-type half-cell was assembled. The obtained battery was subjected to charge-discharge test in an electrochemical workstation, and the test voltage range was 0.01V-3.0V. The test results are shown in Table 1 and Figure 14-16

[0084] Table 1

[0085] Sample Capacity High-rate capacity Example 1 705.2 mAh g -1 @0.2 Ag -1 ]] 368.8 mAh g -1 @10 Ag -1 ]] Example 2 614.1 mAh g -1 @0.2 Ag -1 ]] 378.2 mAh g -1 @10 Ag -1 ]]> Example 3 516.4 mAh g -1 @0.2 Ag -1 ]] 310.6 mAh g -1 @10 Ag -1 ]]

[0086] Figure 14 The test results of Example 1 show that the 2H phase MoS2 nanowire sodium ion battery anode exhibits a high capacity of 705.2mAh g -1 . Figure 15 The rate performance test results of Example 1 show that the 2H phase MoS2 nanowire still has a good rate performance of 368.8mAh g -1 at a current density of 10A g -1 . Figure 16 The cycle performance test results of Example 1 show that the 2H phase MoS2 nanowire has a long cycle life of 9700 cycles at a current density of 5A g -1 .

[0087] Although the specific embodiments of the present application are described above, those skilled in the art should understand that this is only an example, and the protection scope of the present application is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present application, and such changes and modifications all fall within the protection scope of the present application.​

Claims

1. A one-dimensional 2H phase MoS 1.5 X 0.5 The method for preparing a nanowire material is characterized in that: It includes the following steps: A mixture containing Mo2S3 nanowires and X element is placed in a reaction tube, the reaction tube is vacuumed and sealed, and then calcined at 350-1000°C for 2-20h to obtain the one-dimensional 2H phase MoS 1.5 X 0.5 Nanowire material; wherein X is one or more of S, Se and Te.

2. The one-dimensional 2H phase MoS according to claim 1 1.5 X 0.5 The method for preparing a nanowire material is characterized in that: The molar ratio of the X element to the Mo2S3 nanowires is not less than 1; and / or, the calcination temperature is 500-900° C.; And / or, the calcination time is 3-12 hours.

3. The one-dimensional 2H phase MoS according to claim 2 1.5 X 0.5 The method for preparing a nanowire material is characterized in that: The molar ratio of the X element to the Mo2S3 nanowires is 1-1.2; and / or, the calcination temperature is 500° C., 600° C. or 700° C.; And / or, the calcination time is 3h, 5h or 10h.

4. The one-dimensional 2H phase MoS according to claim 3 1.5 X 0.5 The method for preparing a nanowire material is characterized in that: The molar ratio of the X element to the Mo2S3 nanowires is 1 or 1.

1.

5. The one-dimensional 2H phase MoS according to claim 1 1.5 X 0.5 The method for preparing a nanowire material is characterized in that: When X is Se and / or Te, the calcination temperature is 600-750° C., and the calcination time is 3-12 h.

6. The one-dimensional 2H phase MoS according to claim 5 1.5 X 0.5 The method for preparing a nanowire material is characterized in that: When X is Te, the calcination temperature is 600-750° C., and the calcination time is 8-12 h.

7. The one-dimensional 2H phase MoS according to claim 1 1.5 X 0.5 The method for preparing a nanowire material is characterized in that: The diameter of the Mo2S3 nanowire is 100-600 nm; and / or, the length of the Mo2S3 nanowire is 50-200 μm; And / or, the preparation method of the Mo2S3 nanowires comprises the following steps: placing a mixture of molybdenum powder, sulfur powder, red phosphorus and sodium chloride in a quartz tube, evacuating and sealing the quartz tube, calcining at 750-1200°C for 20-48h, and then washing and drying.

8. The one-dimensional 2H phase MoS according to claim 7 1.5 X 0.5 The method for preparing a nanowire material is characterized in that: The preparation method of the Mo2S3 nanowires satisfies one or more of the following conditions: (1) The molar ratio of the molybdenum powder to the sulfur powder is 2:3; (2) The mass of the red phosphorus is 2%-10% of the sum of the mass of the molybdenum powder and the sulfur powder; (3) The mass of the sodium chloride is 3-8 times the sum of the mass of the molybdenum powder and the sulfur powder; (4) The calcination temperature is 800-1100°C; (5) The calcination time is 24-48 hours.

9. A one-dimensional 2H phase MoS 1.5 X 0.5 Nanowire material, characterized in that The invention is prepared according to the preparation method according to any one of claims 1 to 8.

10. The one-dimensional 2H phase MoS according to claim 9. 1.5 X 0.5 Nanowire material, characterized in that X is one or more of S, Se and Te, and the MoS 1.5 X 0.5 The diameter of the nanowires is 100-800 nm and the length is 50-200 μm.

11. The one-dimensional 2H phase MoS according to claim 10 1.5 X 0.5 Nanowire material, characterized in that The one-dimensional 2H phase MoS 1.5 X 0.5 The diameter of the nanowire material is 200-400 nm; And / or, the one-dimensional 2H phase MoS 1.5 X 0.5 The length of the nanowire material is 100-150 μm.

12. A one-dimensional 2H phase MoS according to any one of claims 9 to 11 1.5 X 0.5 Application of nanowire materials in sodium-ion batteries.

13. A sodium ion battery, characterized in that: It includes the one-dimensional 2H phase MoS according to any one of claims 9 to 11. 1.5 X 0.5 Nanowire materials.

14. The sodium ion battery according to claim 13, wherein The one-dimensional 2H phase MoS 1.5 X 0.5 Nanowire materials are used as negative electrode materials.

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