A bimetallic chalcogenide composite material and its preparation method and application

Abstract

The present invention belongs to the field of nanomaterial technology, and provides a bimetallic chalcogenide composite material, and a preparation method and application thereof. The composite material of the present invention includes a two-dimensional layered carrier, and a first metal chalcogenide and a second metal chalcogenide loaded on the two-dimensional layered carrier; the two-dimensional layered carrier is a MXene material, and the MXene material is an M metallized carbon material; the first metal chalcogenide is MX2; the second metal chalcogenide is AX2; wherein M is a first metal, A is a second metal, and X is a chalcogen element. The present invention uses a two-dimensional layered carrier as a carrier to load the bimetallic chalcogenide, which can make the structure of the bimetallic chalcogenide complete; and the two-dimensional layered carrier can form a stable heterogeneous interface with the bimetallic chalcogenide, which is beneficial to the charge transfer between different components and the rapid storage of lithium ions, so that the composite material can be better applied to the field of lithium storage negative electrodes.

Description

Technical Field

[0001] The present invention relates to the technical field of nanomaterials, and in particular to a bimetallic chalcogenide composite material and a preparation method and application thereof. Background Art

[0002] Transition metal chalcogenides (TMCs) are a typical class of conversion-type lithium storage anode materials with advantages such as high theoretical specific capacity (500-1000mAh / g), safety, and low cost. Transition metal chalcogenides represent a typical class of conversion-type battery materials, which can be represented by the general formula MX n denoted by [metallic metal], where M is a metal element such as Sn, Ti, or Fe, and X represents a chalcogenide element, including sulfur (S), selenium (Se), tellurium (Te), and polonium (Po). During lithium storage, metal chalcogenides first undergo a reduction reaction to form M and Li₂X. Energy is then stored through a reversible redox reaction around Li₂X. Metal chalcogenides are widely used in the study of lithium storage electrode materials due to their high theoretical specific capacity (500–1000 mAh / g), diverse structural types, and rich physical and chemical properties. Different TMCs have distinct energy band structures and exhibit a variety of physical and chemical properties, making TMCs promising for modification and optimization as lithium storage anode materials. However, thermodynamically stable TMCs typically have inherently poor electrical conductivity and experience more severe volume changes during lithiation and delithiation than metal oxides, resulting in poor rate capability and cycling stability. Some studies have attempted to construct bimetallic selenides to address the slow charge transfer within TMC particles by creating heterogeneous interfaces using different bimetallic selenides. The heterogeneous interfaces between these different TMCs can spontaneously generate internal electric fields, promoting the transport of ions and electrons within the material. For example, CoSe2 / SnSe, FeSe2 / CoSe2, Ni3Se4 / CoSe2, etc. have been proven to exhibit faster reaction kinetics and lower lithium ion diffusion barriers during lithium storage. However, the problem of volume expansion and structural collapse of TMCs during charging and discharging has not been solved, and a conductive substrate material with good mechanical properties is often required as a buffer layer to protect the structural integrity of the material. However, traditional carbon material substrates such as graphene cannot form a stable heterogeneous interface with TMCs, which is not conducive to charge transfer between different components and rapid storage of lithium ions. Therefore, it is still a challenge to design and develop a simple and universal method to synthesize bimetallic selenide-based composite materials with good heterogeneous interfaces and stable structures to realize the practical application of TMCs in the field of lithium storage anodes. Summary of the Invention

[0003] In view of this, the object of the present invention is to provide a bimetallic chalcogenide composite material and its preparation method and application. The bimetallic chalcogenide composite material of the present invention has a good heterogeneous interface and a stable structure.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides a bimetallic chalcogenide composite material, comprising a two-dimensional layered support, and a first metal chalcogenide and a second metal chalcogenide supported on the two-dimensional layered support;

[0006] The two-dimensional layered carrier is a MXene material, and the MXene material is an M metallized carbon material;

[0007] The first metal chalcogenide is MX2;

[0008] The second metal chalcogenide is AX2;

[0009] Wherein, M is the first metal, A is the second metal, and X is a chalcogen element.

[0010] Preferably, the M is Ti, Nb or V, and the M metallized carbon material is Ti3C2T x 、Nb2CT x or V2CT x .

[0011] Preferably, A is Co, Sb, Ni, Mn or Zn.

[0012] Preferably, X is S or Se.

[0013] The present invention also provides a method for preparing the bimetallic chalcogenide composite material described in the above technical solution, comprising the following steps:

[0014] Mixing the M metallized carbon material, the A salt and water to perform an adsorption reaction to obtain an adsorption reaction system;

[0015] Adding a reducing agent to the adsorption reaction system to carry out a reduction reaction to obtain an A / M metallized carbon precursor;

[0016] The A / M metallized carbon precursor and chalcogenide element powder are mixed and subjected to a first reaction to obtain the bimetallic chalcogenide composite material.

[0017] Preferably, the mass ratio of the A salt to the M metallized carbon material is 1:1 to 1:5.

[0018] Preferably, the reducing agent is sodium borohydride, and the mass ratio of the reducing agent to salt A is 1:1 to 1:3.

[0019] Preferably, the mass ratio of the chalcogen element powder to the A / M metallized carbon precursor is 1 to 4:1.

[0020] Preferably, the temperature of the first reaction is 500-1000° C., the time is 1-5 hours, and the first reaction is carried out under vacuum conditions.

[0021] The present invention also provides the use of the bimetallic chalcogenide composite material described in the above technical solution or the bimetallic chalcogenide composite material prepared by the preparation method described in the above technical solution in a lithium storage negative electrode.

[0022] The present invention provides a bimetallic chalcogenide composite material, comprising a two-dimensional layered support, and a first metal chalcogenide and a second metal chalcogenide loaded on the two-dimensional layered support; the two-dimensional layered support is a MXene material, and the MXene material is an M-metallized carbon material; the first metal chalcogenide is MX2; the second metal chalcogenide is AX2; wherein M is a first metal, A is a second metal, and X is a chalcogen element.

[0023] The bimetallic chalcogenide combination of the present invention enables the composite material to exhibit faster reaction kinetics and lower lithium ion diffusion barriers during the lithium storage process; at the same time, the bimetallic chalcogenide is loaded on a two-dimensional layered carrier, which can make the structure of the bimetallic chalcogenide complete; and the two-dimensional layered carrier can form a stable heterogeneous interface with the bimetallic chalcogenide, which is beneficial to the charge transfer between different components and the rapid storage of lithium ions, so that the composite material can be better applied in the field of lithium storage negative electrodes.

[0024] The present invention also provides a method for preparing the bimetallic chalcogenide composite material described in the above technical solution, comprising the following steps: mixing an M metallized carbon material, an A salt and water, conducting an adsorption reaction, and obtaining an adsorption reaction system; adding a reducing agent to the adsorption reaction system to conduct a reduction reaction, and obtaining an A / M metallized carbon precursor; mixing the A / M metallized carbon precursor and a chalcogen element powder, and conducting a first reaction, and obtaining the bimetallic chalcogenide composite material.

[0025] The present invention uses an adsorption reaction to adsorb metal ions A onto the surface of a metallized carbon material M. A reducing agent is then added to in situ reduce the adsorbed metal ions A to elemental metal A. Chalcogenide monomer powder is then added to react the M element, which would otherwise be oxidized to MO, directly into metallic 1T-MX2, which can form a bimetallic chalcogenide with AX2 and a large number of heterogeneous interfaces. In the final product, AX2 / MX2 / M metallized carbon material, AX2 / MX2 / bimetallic chalcogenide nanoparticles are uniformly attached to the surface of the M metallized carbon nanosheets, forming a large number of heterogeneous interfaces composed of the two chalcogenides and avoiding the adverse effects of inert metal oxides caused by MXene oxidation in traditional material synthesis processes. Therefore, when AX2 / MX2 / M metallized carbon materials are used as lithium storage negative electrode materials, the high specific capacity of TMCs materials can be fully utilized, and the internal electric field caused by the heterogeneous interface can be used to accelerate the ion migration speed. At the same time, the good mechanical stability of MXene can effectively improve the cycle life of the electrode, achieving a dual improvement in rate performance and cycle stability. Moreover, the preparation method provided by the present invention is simple in process, can be directly scaled up and has the advantage of universal applicability. The prepared AX2 / MX2 / M metallized carbon material composite material has good structural stability. With the continuous increase in the number of MXene types, different types of MXene, adsorbed metal cations and chalcogenide powders can be selected to prepare transition bimetallic chalcogenide / MXene composite materials with different physical and chemical properties for use in energy storage fields such as supercapacitors and lithium-ion batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 CoSe2 / TiSe2 / Ti3C2T prepared in Example 1 x X-ray diffraction patterns of the composite material and pure CoSe2;

[0027] Figure 2 CoSe2 / TiSe2 / Ti3C2T prepared in Example 1 x Composite materials, Ti3C2T x and Raman spectra of CoSe2;

[0028] Figure 3 CoSe2 / TiSe2 / Ti3C2T prepared in Example 1 x Composite materials and Ti3C2T x High-resolution X-ray photoelectron spectroscopy of Ti element;

[0029] Figure 4 CoSe2 / TiSe2 / Ti3C2T prepared in Example 1 x Scanning electron microscopy images of the composite material;

[0030] Figure 5 CoSe2 / TiSe2 / Ti3C2T prepared in Example 1 x Transmission electron microscopy images of the composite material;

[0031] Figure 6 CoSe2 / TiSe2 / Ti3C2T prepared in Example 1 x Element energy spectrum distribution diagram of composite materials;

[0032] Figure 7 CoSe2 / TiSe2 / Ti3C2T prepared in Example 1 x Lithium storage rate performance diagram of composite materials;

[0033] Figure 8 Sb2Se3 / TiSe2 / Ti3C2T prepared in Example 7 x X-ray diffraction patterns of composite materials;

[0034] Figure 9 Sb2Se3 / TiSe2 / Ti3C2T prepared in Example 7 x Scanning electron microscopy images of the composite material;

[0035] Figure 10 Sb2Se3 / TiSe2 / Ti3C2T prepared in Example 7 x Graph of the rate performance of composite materials. DETAILED DESCRIPTION

[0036] The present invention provides a bimetallic chalcogenide composite material, comprising a two-dimensional layered support, and a first metal chalcogenide and a second metal chalcogenide supported on the two-dimensional layered support;

[0037] The two-dimensional layered carrier is a MXene material, and the MXene material is an M metallized carbon material;

[0038] The first metal chalcogenide is MX2;

[0039] The second metal chalcogenide is AX2;

[0040] Wherein, M is the first metal, A is the second metal, and X is a chalcogen element.

[0041] In the present invention, unless otherwise specified, the raw materials used in the present invention are preferably commercially available products.

[0042] The bimetallic chalcogenide composite material provided by the present invention includes a two-dimensional layered support, wherein the two-dimensional layered support is a MXene material, and the MXene material is an M metallized carbon material; the M is preferably Ti, Nb or V, and the M metallized carbon material is specifically preferably Ti3C2T x 、Nb2CT x or V2CT x In the present invention, the number of layers of the M metallized carbon material is preferably a single layer or a few layers. In the present invention, the Ti3C2T x The preparation method preferably comprises the following steps: adding MAX Ti3AlC2 powder to a lithium fluoride-hydrochloric acid aqueous solution, sequentially performing etching and stripping, washing and drying to obtain the Ti3C2T x . In the present invention, the lithium fluoride-hydrochloric acid aqueous solution includes lithium fluoride and hydrochloric acid aqueous solution, the concentration of the hydrochloric acid aqueous solution is preferably 9 mol / L, and the amount ratio of the lithium fluoride and hydrochloric acid aqueous solution is preferably 2g:40mL. In the present invention, the temperature of the etching and stripping is preferably 20 to 50°C, more preferably 30 to 40°C; the time is preferably 15 to 30h, more preferably 24h. In the present invention, the etching and stripping is preferably carried out under stirring. In the present invention, the washing reagent is preferably water, and the present invention does not specifically limit the amount and number of the washing reagent, and washing is performed until the pH value of the washing solution is greater than 6. In the present invention, the drying method is preferably freeze-drying.

[0043] The bimetallic chalcogenide composite material provided by the present invention includes a first metal chalcogenide supported on the two-dimensional layered carrier, wherein the first metal chalcogenide is MX2, and the type of M is consistent with the above technical solution and will not be repeated here; the X is preferably S or Se.

[0044] The bimetallic chalcogenide composite material provided by the present invention includes a second metal chalcogenide supported on the two-dimensional layered support; the second metal chalcogenide is AX2; the A is preferably Co, Sb, Ni, Mn or Zn; the type of the X is preferably consistent with the above technical solution and will not be repeated here.

[0045] The present invention also provides a method for preparing the bimetallic chalcogenide composite material described in the above technical solution, comprising the following steps:

[0046] Mixing the M metallized carbon material, the A salt and water to perform an adsorption reaction to obtain an adsorption reaction system;

[0047] Adding a reducing agent to the adsorption reaction system to carry out a reduction reaction to obtain an A / M metallized carbon precursor;

[0048] The A / M metallized carbon precursor and chalcogenide element powder are mixed and subjected to a first reaction to obtain the bimetallic chalcogenide composite material.

[0049] The present invention mixes M metallized carbon material, A salt and water, and performs adsorption reaction to obtain an adsorption reaction system.

[0050] In the present invention, the salt A is preferably cobalt acetate tetrahydrate, nickel acetate, manganese acetate, zinc acetate or antimony chloride, and more preferably cobalt acetate tetrahydrate.

[0051] In the present invention, the mass ratio of the A salt to the M metallized carbon material is preferably 1:1 to 1:5.

[0052] In the present invention, the mixing of the M metallized carbon material, the A salt, and water preferably includes the following steps: mixing the M metallized carbon material and water to obtain a M metallized carbon material dispersion; and mixing the M metallized carbon material dispersion with the A salt. In the present invention, the mixing of the M metallized carbon material and water is preferably performed under ultrasonic conditions. In the present invention, the concentration of the M metallized carbon material dispersion is preferably 1 to 5 mg / mL, more preferably 2 mg / mL.

[0053] In the present invention, the adsorption reaction temperature is preferably room temperature, that is, no additional heating or cooling is required, and the adsorption reaction time is preferably 1 hour. In the present invention, the adsorption reaction is preferably carried out under stirring.

[0054] After the adsorption reaction, the present invention preferably does not perform any operation.

[0055] In the present invention, during the adsorption reaction, the A metal ion can be adsorbed on the surface of the M metallized carbon material.

[0056] After obtaining the adsorption reaction system, the present invention adds a reducing agent to the adsorption reaction system to carry out a reduction reaction to obtain an A / M metallized carbon precursor.

[0057] In the present invention, the reducing agent is preferably sodium borohydride, and the mass ratio of the reducing agent to the A salt is preferably 1:1 to 1:3.

[0058] In the present invention, the temperature of the reduction reaction is preferably room temperature, that is, no additional heating or cooling is required; the time of the reduction reaction is preferably 1 to 2 hours; and the reduction reaction is preferably carried out under stirring.

[0059] After the reduction reaction, the present invention preferably further comprises: performing solid-liquid separation on the obtained reduction reaction suspension and freeze-drying the obtained solid. In the present invention, the solid-liquid separation method is preferably centrifugation, and the centrifugal speed is preferably 5000-12000 rpm.

[0060] In the present invention, the reduction reaction can reduce the A metal ions adsorbed on the surface of the M metallized carbon material to A metal element.

[0061] After obtaining the A / M metallized carbon precursor, the present invention mixes the A / M metallized carbon precursor with a chalcogen element powder and performs a first reaction to obtain the bimetallic chalcogenide composite material.

[0062] In the present invention, the chalcogen element powder preferably includes sulfur powder or selenium powder.

[0063] In the present invention, the mass ratio of the chalcogen element powder to the A / M metallized carbon precursor is preferably 1 to 4:1, more preferably 3:1.

[0064] In the present invention, the temperature of the first reaction is preferably 500-1000°C, more preferably 600-900°C, more preferably 700-800°C; the time of the first reaction is preferably 1-5h, more preferably 2h; the first reaction is preferably carried out under vacuum conditions, and the vacuum degree of the vacuum is preferably 10 -2 ~10 -3 Pa.

[0065] In the present invention, during the first reaction, the A element and the M metal in the A / M metallized carbon precursor react with the chalcogen element powder to form AX2 and MX2 respectively.

[0066] The present invention also provides the use of the bimetallic chalcogenide composite material described in the above technical solution or the bimetallic chalcogenide composite material prepared by the preparation method described in the above technical solution in a lithium storage negative electrode.

[0067] The present invention does not specifically limit the application method of the bimetallic chalcogenide composite material, and any application method familiar to those skilled in the art can be used.

[0068] The bimetallic chalcogenide composite material provided by the present invention, its preparation method and application are described in detail below with reference to the examples, but they should not be construed as limiting the scope of protection of the present invention.

[0069] Example 1

[0070] (1) 2 g of LiF was dissolved in 9 mol / L HCl aqueous solution (40 mL) to obtain a LiF-HCl aqueous solution; 2 g of Ti3AlC2 was then added to the above solution and stirred at 40 °C for 24 h. Finally, the product was repeatedly washed with clean water until neutral, freeze-dried and stored at low temperature to obtain Ti3C2T x powder.

[0071] (2) Ti3C2T x The powder was directly added into deionized water and ultrasonically dispersed to obtain Ti3C2T x Aqueous solution (2 mg / mL), 0.25 mmol of cobalt acetate tetrahydrate was added to 50 mL of Ti3C2T x After stirring for 1 hour, 50 mg of sodium borohydride was added and the stirring was continued for 1 hour. The suspension was centrifuged at 10000 rpm for several times to remove excess impurities and freeze-dried to obtain liquid phase reduced Co / Ti3C2T x Precursor.

[0072] (3) Then Co / Ti3C2T x The mass ratio of the precursor and selenium powder is 1:3, and the Co / Ti3C2T x After the precursor and selenium powder are mixed, they are heated at 750℃ in a vacuum environment (vacuum degree is 10 -2 Pa) for 2 hours to obtain CoSe2 / TiSe2 / Ti3C2T x Composite materials.

[0073] CoSe2 / TiSe2 / Ti3C2T prepared in this example x The X-ray diffraction spectrum of the composite material is as follows Figure 1 As shown by Figure 1 As shown in the figure, there is almost no Ti3C2T x The characteristic peaks of the oxidation product TiO2 indicate that MXene successfully avoids the oxidation problem in the synthesis strategy of this material.

[0074] CoSe2 / TiSe2 / Ti3C2T prepared in this example x The Raman spectrum of the composite material is shown in Figure 2 As shown, from Figure 2 It can be seen that the overall profile of the curve is similar to that of Ti3C2T x consistent, indicating that the Ti3C2T x The substrate has not undergone any essential changes. In addition, the characteristic vibration peaks of CoSe2 and TiSe2 can be clearly observed, indicating that the CoSe2 / TiSe2 / Ti3C2T x Successful preparation.

[0075] CoSe2 / TiSe2 / Ti3C2T prepared in this example x High-resolution X-ray photoelectron spectroscopy of Ti elements in composite materials Figure 3 As shown, from Figure 3 It can be seen that: compared with pure Ti3C2T xCompared with CoSe2 / TiSe2 / Ti3C2T x Ti in composite materials 4+ The proportion of Ti on the MXene surface has increased significantly, which is due to the low-valent Ti element on the MXene surface being selenized into TiSe2 and then converted into Ti 4+ In addition, there are still other mixed valence Ti element fitting peaks, indicating that the substrate Ti3C2T x No essential changes have occurred.

[0076] CoSe2 / TiSe2 / Ti3C2T prepared in this example x Scanning electron microscopy images of the composite materials Figure 4 As shown, the left and right pictures are scanning electron microscope pictures at different magnifications. Figure 4 It can be seen that the CoSe2 / TiSe2 / Ti3C2T prepared in this embodiment x The two-dimensional nanosheet structure of MXene is still maintained, and the CoSe2 / TiSe2 bimetallic selenide particles are uniformly dispersed in the Ti3C2T x There is no obvious accumulation or shedding on the surface.

[0077] CoSe2 / TiSe2 / Ti3C2T prepared in this example x Transmission electron microscopy images of the composite materials Figure 5 As shown, (a), (b) and (c) are transmission electron microscope images at different magnifications. Figure 5 It can be seen that the CoSe2 / TiSe2 bimetallic selenide particles are uniformly attached to the Ti3C2T x Further magnification within a selected area reveals two distinct lattice fringes: the 0.26nm (210) plane of CoSe2 and the 0.60nm (001) plane of TiSe2. The nanoparticles are composed of two selenides, and the distinct heterojunctions observed indicate the presence of numerous heterojunctions within the particles.

[0078] CoSe2 / TiSe2 / Ti3C2T prepared in this example x The element energy spectrum distribution diagram of the composite material is as follows Figure 6 As shown, from Figure 6 It can be seen that Co, Se, and Ti elements are all distributed on the same particle, proving the successful preparation of CoSe2 / TiSe2 bimetallic selenide particles.

[0079] The electrochemical test method is to test the material performance by assembling a lithium half-cell and mixing different mass ratios of CoSe2 / TiSe2 / Ti3C2T xThe composite material was mixed with conductive carbon black and PVDF and stirred in N-methylpyrrolidone at a mass ratio of 8:1:1. The mixture was coated on copper foil and vacuum dried to obtain an electrode. x The lithium storage rate performance of the composite material is as follows Figure 7 As shown, from Figure 7 It can be seen that the specific capacities at current densities of 0.1, 0.3, 0.5, 1, 2, 3, 5, 8 and 10 A / g are 643.7, 591.1, 578.6, 553.6, 513.9, 461.6, 372.2, 235.2 and 177.5 mAh / g, respectively. When the current density is restored to 0.1 A / g, it still has 610.7 mAh / g. The above results prove that CoSe2 / TiSe2 / Ti3C2T x It has good kinetic performance and high specific capacity in lithium storage applications.

[0080] Example 2

[0081] CoSe2 / TiSe2 / Ti3C2T was prepared according to the method of Example 1 x , the difference from Example 1 is that the amount of cobalt acetate tetrahydrate added in step (2) is adjusted to 0.4 mmol, and the mass ratio of cobalt acetate tetrahydrate to MXene is about 1:1.

[0082] Example 3

[0083] CoSe2 / TiSe2 / Ti3C2T was prepared according to the method of Example 1 x , the difference from Example 1 is that the amount of cobalt acetate tetrahydrate added in step (2) is adjusted to 0.3 mmol, and the mass ratio of cobalt acetate tetrahydrate to MXene is about 1:1.25.

[0084] Example 4

[0085] CoSe2 / TiSe2 / Ti3C2T was prepared according to the method of Example 1 x , which is different from Example 1 in that the Co / Ti3C2T x The mass ratio of precursor to selenium powder is 1:1.

[0086] Example 5

[0087] CoSe2 / TiSe2 / Ti3C2T was prepared according to the method of Example 1 x , which is different from Example 1 in that the Co / Ti3C2T x The mass ratio of precursor to selenium powder is 1:2.

[0088] Example 6

[0089] CoSe2 / TiSe2 / Ti3C2T was prepared according to the method of Example 1 x , which is different from Example 1 in that the Co / Ti3C2T x The mass ratio of precursor to selenium powder is 1:4.

[0090] Example 7

[0091] Sb2Se3 / TiSe2 / Ti3C2T was prepared according to the method of Example 1. x , which differs from Example 1 in that the cobalt acetate tetrahydrate in step (2) is replaced with SbCl 3 of the same mass.

[0092] Sb2Se3 / TiSe2 / Ti3C2T prepared in this example x The X-ray diffraction spectrum of the composite material is as follows Figure 8 As shown by Figure 8 As shown in the figure, there is almost no Ti3C2T x The characteristic peaks of the oxidation product TiO2 were detected, and Sb2Se3 was successfully synthesized, indicating that different non-oxidized MXene composites can be synthesized by replacing the added transition metal ions.

[0093] Sb2Se3 / TiSe2 / Ti3C2T prepared in this example x Scanning electron microscopy images of the composite materials Figure 9 As shown in the figure, it can be seen that the Sb2Se3 / TiSe2 bimetallic selenide particles are uniformly attached to the Ti3C2T x surface.

[0094] The electrochemical test method is to test the material performance by assembling a lithium half-cell, and mixing Sb2Se3 / TiSe2 / Ti3C2T with different mass ratios. x The composite material is mixed with conductive carbon black and PVDF, and stirred in N-methylpyrrolidone at a mass ratio of 8:1:1. The mixture is coated on a copper foil and vacuum dried to obtain an electrode plate. Figure 10 Sb2Se3 / TiSe2 / Ti3C2T x The rate performance of composite materials, from Figure 10 It can be seen that the specific capacities at current densities of 0.1, 0.3, 0.5, 1, 2, 3, 5, 8 and 10 A / g are 356.5, 306.1, 274.9, 234.9, 198.1, 180.9, 154.6, 127.1 and 115.8 mAh / g, respectively. When the current density is restored to 0.1 A / g, it still has a specific capacity of 315.2 mAh / g. The above results prove that Sb2Se3 / TiSe2 / Ti3C2Tx It has good kinetic performance and high specific capacity in lithium storage applications.

[0095] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A bimetallic chalcogenide composite material, characterized in that: It includes a two-dimensional layered support, and a first metal chalcogenide and a second metal chalcogenide supported on the two-dimensional layered support; The two-dimensional layered carrier is a MXene material, and the MXene material is an M metallized carbon material; The first metal chalcogenide is MX2; The second metal chalcogenide is AX2; Wherein, M is the first metal, A is the second metal, and X is a chalcogen element; The M is Ti, Nb or V; A is Co, Sb, Ni, Mn or Zn; The preparation method of the bimetallic chalcogenide composite material comprises the following steps: Mixing the M metallized carbon material, the A salt and water to perform an adsorption reaction to obtain an adsorption reaction system; Adding a reducing agent to the adsorption reaction system to carry out a reduction reaction to obtain an A / M metallized carbon precursor; Mixing the A / M metallized carbon precursor and chalcogenide element powder to perform a first reaction to obtain the bimetallic chalcogenide composite material; The mass ratio of the A salt to the M metallized carbon material is 1:1 to 1:5; The reducing agent is sodium borohydride, and the mass ratio of the reducing agent to salt A is 1:1 to 1:

3.

2. The bimetallic chalcogenide composite material according to claim 1, characterized in that: The M metallized carbon material is Ti3C2T x 、Nb2CT x or V2CT x .

3. The bimetallic chalcogenide composite material according to claim 1, characterized in that: The X is S or Se.

4. The method for preparing the bimetallic chalcogenide composite material according to any one of claims 1 to 3, characterized in that: The following steps are involved: Mixing the M metallized carbon material, the A salt and water to perform an adsorption reaction to obtain an adsorption reaction system; Adding a reducing agent to the adsorption reaction system to carry out a reduction reaction to obtain an A / M metallized carbon precursor; Mixing the A / M metallized carbon precursor and chalcogenide element powder to perform a first reaction to obtain the bimetallic chalcogenide composite material; The mass ratio of the A salt to the M metallized carbon material is 1:1 to 1:5; The reducing agent is sodium borohydride, and the mass ratio of the reducing agent to salt A is 1:1 to 1:

3.

5. The preparation method according to claim 4, characterized in that The mass ratio of the chalcogen element powder to the A / M metallized carbon precursor is 1-4:

1.

6. The preparation method according to claim 4 or 5, characterized in that The temperature of the first reaction is 500-1000° C., the time is 1-5 hours, and the first reaction is carried out under vacuum conditions.

7. Use of the bimetallic chalcogenide composite material according to any one of claims 1 to 3 or the bimetallic chalcogenide composite material prepared by the preparation method according to any one of claims 4 to 6 in a lithium storage negative electrode.

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