An alkali metal ion intercalated transition metal chalcogenide and a method of making and using the same

Abstract

The application belongs to the technical field of chemical synthetic materials, and relates to an alkali metal ion intercalated transition metal chalcogenide compound as well as a preparation method and application thereof. x M m X n wherein A is one or more of alkali metal elements, and 0 < x < 1; M is one or more of transition metal elements, and m is 1-2; X is one or more of chalcogen elements, and n is 1-3; and the alkali metal ion intercalated transition metal chalcogenide compound is obtained by mixing and reacting an intercalation host transition metal chalcogenide compound, an intercalation guest alkali metal element-containing compound and an auxiliary metal intercalation agent.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical synthesis materials and relates to an alkali metal ion intercalated transition metal sulfide compound and a preparation method and application thereof. Background Art

[0002] Alkali metal intercalated transition metal chalcogenides have been widely used in the field of energy conversion and storage devices, especially Li + Intercalation compounds play a crucial role in the search for alternative clean energy sources for lithium-ion batteries. Alkali metal intercalation not only increases the interlayer spacing, but the introduction of alkali metal ions also enhances the overall conductivity, ion transport, and reversible structural stability of the layered material. Consequently, layered transition metal chalcogenides possess high theoretical specific capacity and safety, garnering widespread attention in the field of anode materials.

[0003] Transition metal chalcogenides are a type of van der Waals layered material. Their atomic layers are mainly divided into two types: XMX or XMXMX structures, depending on the metal element. The layers are bonded by strong metallic bonds or covalent bonds, and the layers are bonded by weak van der Waals interactions with a certain interlayer spacing. The openness of their structure allows alkali metal ions to enter the van der Waals gap, forming a non-van der Waals layered material with alkali metal intercalation. The structural formula of this intercalation compound can be abbreviated as A according to the difference in atoms and concentration. x M m S n . This layered intercalation product has the characteristics of structural openness and stability, which can achieve relatively fast ion diffusion, which is beneficial to alleviate the volume expansion caused by the insertion / extraction of alkali metal ions during battery cycling. In addition, the intrinsic electronic structure of transition metal chalcogenides is usually affected by guest ions, and this electronic disturbance can also cause unexpected changes in physical properties, such as charge density waves, anisotropic transport and even superconductivity. Therefore, the study of alkali metal ion intercalation is not only conducive to solving the energy crisis, but also has guiding significance for the expansion of intercalation chemistry and other intercalation compounds.

[0004] Opposition + For the intercalation of Li, the general method of intercalation is the solvent method, in which the layered sulfide needs to be mixed with an organic solution such as n-butyl lithium n-hexane solution. Although this method can ensure the + However, the conditions are harsh and require isolation of water and oxygen in N2 atmosphere. The experimental process is complex and poses a great safety hazard. Alternatively, alkali metal ions are inserted into the interlayer of transition metal chalcogenides by electrochemical methods, where the transition metal chalcogenides are used as working electrodes, including Li + solution as the electrolyte, and then use the external current as the driving force, accompanied by the layered sulfide and Li +The redox reaction enters the van der Waals gap between the layers, but this method has high requirements for the selection of the electrochemical reaction window, and it is necessary to avoid the decomposition or replacement of transition metal chalcogenides under the action of electric current.

[0005] In addition, although lithium-ion batteries have excellent performance and high stability, the low reserves of lithium resources limit the development of lithium-ion batteries. + / K + , and Li + With similar physical and chemical properties and abundant reserves, sodium / potassium ion batteries have attracted widespread attention. + , other alkali metal ions Na + , K + , Rb + 、Cs + The plasma radius is large and the redox potential is high, which is similar to Li + Comparatively speaking, the intercalation is more difficult. Undoubtedly, there is still a lot of room for the expansion and application of alkali metal intercalated transition metal chalcogenides in the research of intercalation chemistry, including intercalation methods. Summary of the Invention

[0006] The purpose of the present invention is to address the deficiencies in the prior art and provide an alkali metal ion intercalated transition metal chalcogenide and a preparation method thereof, as well as applications of the alkali metal ion intercalated transition metal chalcogenide.

[0007] One object of the present invention is to provide an alkali metal ion intercalated transition metal sulfide compound, the molecular formula of which is A x M m X n , wherein A is one or more alkali metal elements, and 0<x≤1; M is one or more transition metal elements, and m is 1-2; X is one or more chalcogen elements, and n is 1-3.

[0008] Alkali metal elements refer to the six metal elements in Group IA of the periodic table except hydrogen (H), namely lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr); transition metal elements refer to the elements in Groups IIIB to VIIB and VIII of the periodic table; chalcogen elements refer to sulfur (S), selenium (Se), and tellurium (Te).

[0009] Preferably, A is one or more of Li, Na, K, Rb, and Cs; M is one or more of Group IIIB, IVB, VB, and VIB elements; and X is one or both of S and Se. More preferably, M is one or more of Ti, V, Zr, Nb, Mo, Hf, Ta, and W.

[0010] Preferably, the unit cell of the alkali metal ion intercalated transition metal chalcogenide is composed of M m X n The units are stacked alternately with A-layer atoms.

[0011] Preferably, the alkali metal ion intercalated transition metal chalcogenide compound is obtained by mixing an intercalation host transition metal chalcogenide compound, an intercalation guest compound containing an alkali metal element, and an auxiliary metal intercalation agent.

[0012] The present invention uses a transition metal chalcogenide as the intercalation host and an alkali metal-containing compound as the intercalation guest. An auxiliary metal intercalant is used to trigger a redox reaction, thereby inserting the alkali metal into the van der Waals gap of the transition metal chalcogenide. The auxiliary intercalant is partially dissolved in a strongly polarized alkali metal molten salt and provides solvated electrons. Subsequently, the potential difference generated by the electron transfer serves as the driving force, triggering the alkali metal intercalation reaction.

[0013] Preferably, the molar ratio of the transition metal chalcogenide, the auxiliary metal intercalant and the compound containing the alkali metal element is 1:(0-3]:[1-25], where brackets "[" or "]" indicate that the endpoint values ​​are included, and brackets "(" indicate that the endpoint values ​​are not included.

[0014] Preferably, the transition metal chalcogenide has the molecular formula M m X n , wherein M is one or more transition metal elements, and m is 1 to 2; X is one or more chalcogen elements, and n is 1 to 3; M and X of the transition metal chalcogenide are the same as M and X in the alkali metal ion intercalation transition metal chalcogenide.

[0015] Preferably, the auxiliary metal intercalant is one or more of Ti, V, Ga, Ge, Sr, Y, Zr, Nb, and Mo.

[0016] Preferably, the compound containing an alkali metal element comprises an alkali metal halide, which may be an alkali metal halide, or a mixture of an alkali metal halide and an alkali metal sulfide. An alkali metal halide is a binary compound formed by a halogen element and an alkali metal element, and has the molecular formula AY, where A is an alkali metal element and Y is a halogen element. An alkali metal sulfide is a binary compound formed by sulfur and an alkali metal element, and has the molecular formula A2S, where A is an alkali metal element.

[0017] More preferably, the molecular formula of the alkali metal halide is AY, wherein A is an alkali metal element, and Y is Cl and / or Br.

[0018] Preferably, the transition metal chalcogenide compound is in the form of powder with an average particle size of 1 to 100 μm.

[0019] Preferably, the auxiliary metal intercalant is a powder with an average particle size of 0.5 to 50 μm.

[0020] Preferably, the compound containing alkali metal elements is in the form of powder with an average particle size of 500 nm to 1 mm.

[0021] Preferably, the transition metal chalcogenide has a layered structure.

[0022] Preferably, the mixing reaction is carried out in an inert atmosphere at 300-1000°C for 0-5 h (excluding 0). The reaction temperature can be 300, 400, 500, 600, 700, 800, 900, or 1000°C, but is not limited to the values ​​listed above. Other values ​​not listed within the numerical range are also applicable. The reaction time can be 1, 2, 3, 4, or 5 h, but is not limited to the values ​​listed above. Other values ​​not listed within the numerical range are also applicable.

[0023] Preferably, the inert atmosphere comprises nitrogen or argon.

[0024] Preferably, after the mixing reaction, post-treatment is performed, which includes washing and drying. The obtained reaction product is washed with water and then dried at 60-120°C.

[0025] Another object of the present invention is to provide a method for preparing an alkali metal ion intercalated transition metal chalcogenide, comprising the following steps:

[0026] The intercalation host transition metal chalcogenide, the intercalation guest compound containing alkali metal elements and the auxiliary metal intercalation agent are mixed, and the mixture is subjected to high temperature reaction in an inert atmosphere to obtain the alkali metal ion intercalation transition metal chalcogenide.

[0027] In the above preparation method, the mixing method includes but is not limited to grinding, stirring, shaking, etc.

[0028] In the above preparation method, the high temperature reaction is: reacting at 300-1000° C. for 0-5 h (excluding 0) in an inert atmosphere.

[0029] In the above preparation method, after the mixing reaction, post-treatment is performed, and the post-treatment includes washing and drying. The obtained reaction product is washed with water and then dried at 60-120°C.

[0030] Another object of the present invention is to provide an application of an alkali metal ion intercalated transition metal sulfide compound in the preparation of an energy storage material.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The present invention uses a transition metal chalcogenide as an intercalation host and a compound containing an alkali metal element as an intercalation guest, and utilizes an auxiliary metal intercalation agent to initiate a redox reaction, thereby inserting the alkali metal element into the van der Waals gap of the transition metal chalcogenide to obtain an alkali metal ion intercalated transition metal chalcogenide;

[0033] 2. The method for preparing alkali metal ion intercalated transition metal chalcogenide compounds of the present invention is simple, does not require the use of alkali metal elements or non-aqueous alkali metal ion solutions as reaction sources, and does not require harsh conditions such as isolation from water and oxygen during the intercalation process;

[0034] 3. The preparation method of the alkali metal ion intercalated transition metal chalcogenide provided by the present invention can more effectively realize the composition design of the target product;

[0035] 4. The alkali metal ion intercalated transition metal sulfide prepared by the present invention has excellent application prospects in energy storage materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Li prepared in Example 1 x Comparison of XRD patterns of NbS2 and initial NbS2;

[0037] Figure 2 Li prepared in Example 1 x SEM image of NbS2;

[0038] Figure 3 Li prepared in Example 1 x High-resolution transmission electron microscopy image of NbS2;

[0039] Figure 4a and Figure 4b They are the initial NbS2 and Li prepared in Example 1 observed along the same crystal axis. x Electron diffraction pattern of NbS2;

[0040] Figure 5 Li prepared in Example 2 x Scanning electron microscope image of TaS2;

[0041] Figure 6 The Na prepared in Example 3 x Comparison of XRD patterns of NbS2 and initial NbS2;

[0042] Figure 7 The Na prepared in Example 3 was observed along the

[0001] crystal axis. x Electron diffraction pattern of NbS2;

[0043] Figure 8 It is Na prepared in Example 4 x Comparison of XRD patterns of TaS2 and initial TaS2;

[0044] Figure 9 It is Na prepared in Example 4 x Scanning electron microscope image of TaS2;

[0045] Figure 10 It is Na prepared in Example 4 x EDS analysis of TaS2;

[0046] Figure 11 is Rb prepared in Example 5 x Comparison of XRD patterns of NbS2 and initial NbS2;

[0047] Figure 12 Rb observed along the same crystal axis x Comparison of electron diffraction patterns of NbS2;

[0048] Figure 13 It is Cs observed along the same crystal axis x EDS analysis diagram of NbS2. DETAILED DESCRIPTION

[0049] Below by specific embodiment and accompanying drawing, technical scheme of the present invention is further described explanation, it should be understood that specific embodiment described herein is only for helping to understand the present invention, is not used for specific limitation of the present invention.And accompanying drawing used herein, is only for better illustrating the disclosure of the present invention, does not have limiting effect on protection scope.If no special instructions, the raw materials adopted in the embodiment of the present invention are all raw materials commonly used in this area, and the method adopted in the embodiment is all conventional method in this area.

[0050] Example 1

[0051] The molecular formula of the alkali metal ion intercalated transition metal chalcogenide compound in this embodiment is Li x NbS2, 0<x≤1, which is obtained by mixing and reacting the intercalation host transition metal chalcogenide, the intercalation guest compound containing alkali metal elements and the auxiliary metal intercalation agent, wherein the transition metal chalcogenide is NbS2, the compound containing alkali metal elements is LiCl, and the auxiliary metal intercalation agent is Ga particles, and these raw materials can be obtained through commercial channels. x The specific preparation method of NbS2 is as follows:

[0052] (a) Weighing 5 g of LiCl salt with an average particle size of 50 μm, 1.9 g of NbS2 powder with an average particle size of 30 μm, and 0.2 g of Ga particles with a particle size of 10 μm, these materials were ground and mixed to obtain a mixture;

[0053] (2) placing the mixture in a corundum crucible and placing it in a high-temperature tube furnace for reaction under the following conditions: 700°C, 30 minutes, argon protection; after the temperature of the tube furnace drops to room temperature, taking out the reaction product in the crucible;

[0054] (3) Washing the reaction product with deionized water: Place the reaction product in a beaker, add deionized water, stir and ultrasonically clean for 30 minutes, then let it stand for 1 hour and discard the supernatant; after washing the reaction product three times, place it in an oven at 80°C and take it out after 24 hours to obtain a solid product.

[0055] Figure 1 Li prepared in Example 1 x Comparison of the XRD patterns of NbS2 and the initial NbS2 shows that the XRD peaks of the two are similar overall, with an obvious angle shift of the diffraction peak along the (0001) plane orientation, and no other new substance peaks are generated. This shows that the interlayer spacing of the NbS2 sheets increases during the intercalation process, without destroying the original structure and showing a layered structure in the microscopic morphology. The position of the (0003) plane diffraction peak can be used to determine the position of the Li x The c value of the lattice constant of NbS2 is 0.64nm, which shows a significant expansion of the interlayer spacing compared to the c value of 0.59nm of the lattice constant of TiS2. The difference between the XRD patterns of the two is only the difference in the position of the diffraction peak. This phenomenon is because the insertion of Li ions leads to the expansion of the original NbS2 interlayer spacing, showing that the lattice parameters of the two are different. The XRD data fully illustrates that the Li prepared in this example x The crystal structure of NbS2 material is similar to that of NbS2, and it is a ternary intercalated transition metal chalcogenide with a hexagonal layered structure.

[0056] Figure 2 It's Li x The morphology of NbS2 shows that Li x No decomposition or corrosion of the sheets occurred during the NbS2 intercalation process.

[0057] Figure 3 It's Li x High-resolution transmission electron microscopy image of NbS2, the crystal plane stripes of the (0001) crystal plane are clearly visible in the HRTEM image.

[0058] Figure 4a and Figure 4bThe initial NbS2 and Li observed along the same crystal axis x The electron diffraction comparison diagram of NbS2 shows that Li exists in an orderly manner in the van der Waals gap. The satellite spots with weaker brightness in the figure are superlattice diffraction produced by Li insertion.

[0059] Example 2

[0060] The molecular formula of the alkali metal ion intercalated transition metal chalcogenide compound in this embodiment is Li x TaS2, 0<x≤1, which is obtained by mixing and reacting the intercalation host transition metal chalcogenide, the intercalation guest compound containing alkali metal elements and the auxiliary metal intercalation agent, wherein the transition metal chalcogenide is TaS2, the compound containing alkali metal elements is LiBr, and the auxiliary metal intercalation agent is Nb powder, and these raw materials can be obtained through commercial channels. x The specific preparation method of TaS2 is as follows:

[0061] (1) Weigh 8.68 g of LiBr with an average particle size of 60 μm, 1.4 g of TaS2 powder with an average particle size of 40 μm, and 0.9 g of Nb powder with an average particle size of 10 μm, grind and mix the above materials to obtain a mixture;

[0062] (2) Place the mixture in a corundum crucible and place it in a high-temperature tube furnace for reaction. The reaction conditions are: 800°C, 30 minutes, argon protection. After the temperature of the tube furnace drops to room temperature, remove the reaction product from the crucible;

[0063] (3) Washing the reaction product with deionized water: Place the reaction product in a beaker, add deionized water, stir and ultrasonically clean for 20 minutes, then let it stand for 1.5 hours and discard the supernatant. After washing the reaction product three times, place it in a 90°C oven and remove it after 24 hours to obtain a solid product.

[0064] Figure 5 Li prepared in Example 2 x Morphology of TaS2, Li + The insertion leads to the exfoliation of TaS2 sheets, and the curled morphology of the exfoliated TaS2 sheets can be seen in the figure.

[0065] Example 3

[0066] The molecular formula of the alkali metal ion intercalated transition metal chalcogenide compound in this embodiment is Na xNbS2, 0<x≤1, which is obtained by mixing and reacting the intercalation host transition metal chalcogenide, the intercalation guest compound containing alkali metal elements and the auxiliary metal intercalation agent, wherein the transition metal chalcogenide is NbS2, the compound containing alkali metal elements is NaCl, and the auxiliary metal intercalation agent is Ti powder, and these raw materials can be obtained through commercial channels. x The specific preparation method of NbS2 is as follows:

[0067] (1) Weigh 5.84 g of NaCl with an average particle size of 60 μm, 0.9 g of NbS2 powder with an average particle size of 30 μm, and 0.1 g of Ti powder with an average particle size of 10 μm, grind and mix the above materials to obtain a mixture;

[0068] (2) placing the mixture in a corundum crucible and placing it in a high-temperature tube furnace for reaction under the following conditions: 800°C, 30 minutes, argon protection; after the temperature of the tube furnace drops to room temperature, taking out the reaction product in the crucible;

[0069] (3) Washing the reaction product with deionized water: Place the reaction product in a beaker, add deionized water, stir and ultrasonically clean for 20 minutes, then let it stand for 2 hours and discard the supernatant. After washing the reaction product three times, place it in an oven at 85°C and remove it after 24 hours to obtain a solid product.

[0070] Figure 6 The Na prepared in Example 3 x Comparison of the XRD patterns of NbS2 and initial NbS2 shows that the XRD peak types of the two are similar overall and no impurity peaks appear, but sharp small-angle diffraction peaks appear, which indicates that Na insertion not only expands the interlayer spacing but also produces new crystal planes.

[0071] Figure 7 It is the Na observed along the

[0001] crystal axis. x The electron diffraction pattern of NbS2 shows that Na exists in an orderly manner in the van der Waals gap. The satellite spots with weaker brightness in the pattern are superlattice diffraction produced by Na insertion.

[0072] Example 4

[0073] The molecular formula of the alkali metal ion intercalated transition metal chalcogenide compound in this embodiment is Na x TaS2, 0<x≤1, which is obtained by mixing and reacting the intercalation host transition metal chalcogenide, the intercalation guest compound containing alkali metal elements and the auxiliary metal intercalation agent, wherein the transition metal chalcogenide is TaS2, the compound containing alkali metal elements is NaBr, and the auxiliary metal intercalation agent is V powder, and these raw materials can be obtained through commercial channels.x The specific preparation method of TaS2 is as follows:

[0074] (1) 10.3 g of NaBr with an average particle size of 20 μm, 1.2 g of TaS2 powder with an average particle size of 10 μm, and 0.2 g of V powder with an average particle size of 10 μm were weighed and mixed by grinding to obtain a mixture;

[0075] (2) The mixture was placed in a corundum crucible and put into a high-temperature tube furnace for reaction, and the reaction conditions were as follows: 850°C, 30 minutes, and argon protection. After the temperature of the tube furnace dropped to room temperature, the reaction product in the crucible was taken out.

[0076] (3) The reaction product was washed with deionized water: the reaction product was put into a beaker, deionized water was added, and after stirring and ultrasonic cleaning for 50 minutes, it was left to stand for 2 hours, and the supernatant was poured out. After the reaction product was washed three times, it was put into an oven at 80°C, and after 24 hours, it was taken out to obtain a solid product.

[0077] Figure 8 Na x The XRD pattern of TaS2 and the initial TaS2 is shown in the comparison chart. It can be seen from the comparison that the overall peak shape of the XRD patterns of the two is similar and no impurity peak appears, but a sharp small-angle diffraction peak appears, which shows that the Na insertion not only expands the interlayer spacing but also produces a new crystal face.

[0078] Figure 9 Na x The SEM morphology analysis chart of TaS2 is shown in the comparison chart. It can be seen more clearly from the chart that there is no precipitate attached to the surface of the sheet layer, and it presents a clear accordion-like shape after being peeled off, which is consistent with the phenomenon of the new peak appearing in the XRD.

[0079] Figure 10 Na x The EDS analysis chart of TaS2 is shown in the comparison chart. It can be seen more clearly from the chart that there is only Na intercalation in the sheet layer, and no other impurities.

[0080] Example 5

[0081] The molecular formula of the alkali metal ion intercalated transition metal chalcogenide compound in this example is Rb x NbS2, 0 < x ≤ 1, which is obtained by mixing and reacting an intercalation host transition metal chalcogenide, an intercalation guest alkali metal element-containing compound, and an auxiliary metal intercalation agent, wherein the transition metal chalcogenide is NbS2, the alkali metal element-containing compound is RbBr, and the auxiliary metal intercalation agent is Ga particle. These raw materials can be obtained by market purchase or the like. The Rb x The specific preparation method of Rb

[0082] (1) Weigh 9.5 g of RbBr with an average particle size of 65 μm, 0.9 g of NbS2 powder with an average particle size of 30 μm, and 0.4 g of Ge powder with an average particle size of 20 μm, grind and mix the above materials to obtain a mixture;

[0083] (2) Place the mixture in a corundum crucible and place it in a high-temperature tube furnace for reaction. The reaction conditions are: 850°C, 30 minutes, argon protection. After the temperature of the tube furnace drops to room temperature, remove the reaction product from the crucible;

[0084] (3) Washing the reaction product with deionized water: Place the reaction product in a beaker, add deionized water, stir and ultrasonically clean for 50 minutes, then let it stand for 1 hour and discard the supernatant. After washing the reaction product three times, place it in an 80°C oven and remove it after 24 hours to obtain a solid product.

[0085] Figure 11 is Rb prepared in Example 5 x Comparison of XRD patterns of NbS2 and initial NbS2, Rb x The XRD spectrum of NbS2 has a significant difference in peak shape from that of the initial NbS2, but its diffraction peak at low angles is the expansion of the interplanar spacing caused by the insertion of Rb, and this phase does not belong to any existing phase but is a new phase obtained by intercalation.

[0086] Figure 12 Rb observed along the same crystal axis x The electron diffraction pattern of NbS2 shows that Rb exists in an orderly manner in the van der Waals gap. The satellite spots with weaker brightness in the pattern are superlattice diffraction produced by Rb insertion.

[0087] Example 6

[0088] The molecular formula of the alkali metal ion intercalated transition metal chalcogenide compound in this embodiment is Rb x TaS2, 0<x≤1, which is obtained by mixing and reacting the intercalation host transition metal chalcogenide, the intercalation guest compound containing alkali metal elements and the auxiliary metal intercalation agent, wherein the transition metal chalcogenide is TaS2, the compound containing alkali metal elements is RbCl, and the auxiliary metal intercalation agent is V powder, and these raw materials can be obtained through commercial channels. x The specific preparation method of TaS2 is as follows:

[0089] (1) Weigh 6.03 g of RbCl with an average particle size of 30 μm, 3.1 g of TaS2 powder with an average particle size of 15 μm, and 0.25 g of V powder with an average particle size of 10 μm, grind and mix the above materials to obtain a mixture;

[0090] (2) Put the mixture into a corundum crucible and put it into a high-temperature tube furnace to react under the following conditions: 850°C, 30 minutes, and argon protection. After the temperature of the tube furnace drops to room temperature, take out the reaction product in the crucible;

[0091] (3) Wash the reaction product with deionized water: put the reaction product into a beaker, add deionized water, stir and ultrasonically clean for 30 minutes, then stand for 1 hour, and pour off the supernatant. After washing the reaction product three times, put it into an oven at 70°C, and take it out after 24 hours to obtain a solid product.

[0092] Example 7

[0093] The alkali metal ion intercalated transition metal chalcogenide compound of this example has a molecular formula of Cs x NbS2, 0 < x < 1, which is obtained by mixing and reacting an intercalation host transition metal chalcogenide, an intercalation guest alkali metal element-containing compound, and an auxiliary metal intercalation agent, wherein the transition metal chalcogenide is NbS2, the alkali metal element-containing compound is CsBr, and the auxiliary metal intercalation agent is Ga particles, and these raw materials can be obtained by commercial channels. The Cs x NbS2is prepared as follows:

[0094] (1) Weigh 7 g of CsBr with an average particle size of 65 μm, 0.9 g of NbS2powder with an average particle size of 30 μm, and 0.4 g of Mo powder with an average particle size of 20 μm, and grind and mix the above materials to obtain a mixture;

[0095] (2) Put the mixture into a corundum crucible and put it into a high-temperature tube furnace to react under the following conditions: 650°C, 30 minutes, and argon protection. After the temperature of the tube furnace drops to room temperature, take out the reaction product in the crucible;

[0096] (3) Wash the reaction product with deionized water: put the reaction product into a beaker, add deionized water, stir and ultrasonically clean for 30 minutes, then stand for 1 hour, and pour off the supernatant. After washing the reaction product three times, put it into an oven at 70°C, and take it out after 24 hours to obtain a solid product.

[0097] Figure 13 is Cs x NbS2. The content of Cs in the NbS2layer can be clearly seen from the electron diffraction pattern.

[0098] Example 8

[0099] The alkali metal ion intercalated transition metal chalcogenide compound of this example has a molecular formula of Li xTiSe2, 0<x≤1, which is obtained by mixing and reacting the intercalation host transition metal chalcogenide, the intercalation guest compound containing alkali metal elements and the auxiliary metal intercalation agent, wherein the transition metal chalcogenide is TiSe2, the compound containing alkali metal elements is LiBr, and the auxiliary metal intercalation agent is Zr powder, and these raw materials can be obtained through commercial channels. x The specific preparation method of TiSe2 is the same as that of Example 1, and the molar ratio of each raw material is the same as that of Example 1, except that the reaction temperature and time are 600°C and 60 minutes respectively. Other aspects are the same as those of Example 1.

[0100] Example 9

[0101] The molecular formula of the alkali metal ion intercalation transition metal chalcogenide of this embodiment is NaZrSe2, a value in the range of 0<x≤1, which is obtained by mixing and reacting the intercalation host transition metal chalcogenide, the intercalation guest compound containing alkali metal elements and the auxiliary metal intercalation agent, wherein the transition metal chalcogenide is ZrSe2, the compound containing alkali metal elements is NaCl, and the auxiliary metal intercalation agent is Ge powder. These raw materials can be obtained through commercial channels. x The specific preparation method of TiSe2 is the same as that of Example 1, and the molar ratio of each raw material is the same as that of Example 1, except that the reaction temperature and time are 900°C and 20 minutes respectively. Other aspects are the same as those of Example 1.

[0102] Comparative Example 1

[0103] The difference between Comparative Example 1 and Example 1 is that no auxiliary metal intercalant Ga is added in Example 1, and the rest is the same as Example 1.

[0104] In Comparative Example 1, due to the absence of auxiliary metal intercalation agent, the entire reaction has no reaction driving force, so the intercalation product Li cannot be obtained. x NbS2.

[0105] Given the numerous embodiments of the present invention and the extensive experimental data required for each, it is not appropriate to list them all here. However, the content required for verification and the final conclusions obtained in each embodiment are similar, and all can produce alkali metal ion intercalated transition metal chalcogenides. Therefore, the above embodiments are used here as representatives to illustrate the advantages of the present invention.

[0106] The various aspects, embodiments, and features of the present invention should be considered in all respects as illustrative and not limiting, the scope of which is defined solely by the claims. Other embodiments, modifications, and uses will be apparent to those skilled in the art without departing from the spirit and scope of the invention as claimed.

[0107] In the preparation method of the present invention, the order of the steps is not limited to the order listed. Persons skilled in the art will appreciate that variations in the order of the steps are within the scope of the present invention without inventive effort. Furthermore, two or more steps or actions may be performed simultaneously.

[0108] Finally, it should be noted that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit its implementation. Persons skilled in the art may make various modifications, additions, or substitute similar methods for the described specific embodiments. It is not necessary and impossible to provide comprehensive examples of all implementations here. However, obvious variations or modifications arising from the essential spirit of the present invention remain within the scope of protection of the present invention, and interpreting them as any additional limitations would be contrary to the spirit of the present invention.

Claims

1. A method for preparing an alkali metal ion intercalated transition metal chalcogenide, characterized in that: The following steps are involved: The intercalation host transition metal chalcogenide, the intercalation guest compound containing an alkali metal element and the auxiliary metal intercalation agent are mixed, and the mixture is reacted at 300-1000° C. in an inert atmosphere for 0-5 h, excluding 0, to obtain the alkali metal ion intercalation transition metal chalcogenide; The molecular formula of transition metal chalcogenides is M m X n , wherein M is one or more transition metal elements, and m is 1 to 2; X is one or more chalcogen elements, and n is 1 to 3; The auxiliary metal intercalant is one or more of Ti, V, Ga, Ge, Sr, Y, Zr, Nb, and Mo; Compounds containing alkali metal elements include alkali metal halides; The molecular formula of the prepared alkali metal ion intercalated transition metal chalcogenide is A x M m X n , wherein A is one or more alkali metal elements, and 0<x≤1; M is one or more transition metal elements, and m is 1-2; X is one or more chalcogen elements, and n is 1-3.

2. The preparation method according to claim 1, wherein A is one or more of Li, Na, K, Rb, and Cs; M is one or more of Group IIIB, IV B, VB, and VIB elements; and X is one or both of S and Se.

3. The preparation method according to claim 1 or 2, characterized in that M is one or more of Ti, V, Zr, Nb, Mo, Hf, Ta, and W.

4. The preparation method according to claim 1, characterized in that The molar ratio of the transition metal sulfide compound, the auxiliary metal intercalant and the compound containing the alkali metal element is 1:(0-3]:[1-25].

5. The preparation method according to claim 1, characterized in that The transition metal chalcogenide compound is in the form of powder with an average particle size of 1 to 100 μm.

6. The preparation method according to claim 1, characterized in that The auxiliary metal intercalation agent is powder with an average particle size of 0.5 to 50 μm.

7. The preparation method according to claim 1, characterized in that The compound containing the alkali metal element is in the form of powder, and the average particle size is 500nm to 1mm.

8. An alkali metal ion intercalated transition metal chalcogenide prepared by the preparation method according to claim 1, characterized in that: The molecular formula of the alkali metal ion intercalated transition metal chalcogenide is A x M m X n , wherein A is one or more of Li, Na, K, Rb, and Cs, and 0<x≤1; M is one or more of Group IIIB, IV B, VB, and VIB elements, and m is 1 to 2; X is one or two of S and Se, and n is 1 to 3.

9. The alkali metal ion intercalated transition metal chalcogenide according to claim 8, characterized in that: M is one or more of Ti, V, Zr, Nb, Mo, Hf, Ta, and W.

10. Use of the alkali metal ion intercalated transition metal chalcogenide compound according to claim 1 in the preparation of energy storage materials.

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