A three-dimensional hierarchical porous MoS2 material, its preparation method, and its application in fast-charging sodium-ion batteries.

Abstract

This invention discloses a three-dimensional hierarchical porous MoS2 material, its preparation method, and its application in fast-charging sodium-ion batteries, belonging to the fields of porous functional material synthesis and fast-charging sodium-ion battery technology. This invention mainly utilizes a dendritic mesoporous SiO2 nanosphere hard template and two surfactant micellar soft templates to synergistically construct a three-dimensional hierarchical porous structure composed of mesopores and macropores. The mesopores are mainly distributed in the small size range of 2–10 nm, with a most probable pore diameter of 2.5–4.5 nm and a specific surface area of ​​40–45 m². 2 / g, pore volume is 0.15~0.25cm³ 3 The MoS2 material exhibits a few-layer structure, with 1 to 6 layers and an interlayer spacing of 0.68 to 0.71 nm. This three-dimensional hierarchical porous MoS2 material can be used to prepare sodium-ion battery anodes that possess ultra-high rate capability, excellent fast-charging performance, and cycle stability.

Description

Technical Field

[0001] This invention relates to the fields of porous functional material synthesis and fast-charging sodium-ion battery technology, and in particular to a three-dimensional hierarchical porous MoS2 material, its preparation method, and its application in fast-charging sodium-ion batteries. Background Technology

[0002] Sodium-ion batteries (SIBs) are considered one of the most promising lithium-ion battery alternatives due to their energy storage mechanism similar to lithium-ion batteries, as well as the advantages of widely available sodium resources, low raw material costs, and environmental friendliness. Especially in large-scale energy storage systems and high-power fast-charging scenarios (such as grid peak shaving and short-term backup power), sodium-ion batteries demonstrate broad application prospects due to their excellent safety and response speed. Compared to lithium-ion batteries, sodium ions have shorter diffusion paths and faster insertion / extraction reactions in various non-graphite anode materials, while also having higher insertion / extraction potentials, which facilitates faster electrochemical responses. Furthermore, sodium-ion batteries have lower overall manufacturing costs, contributing to the commercialization of low-cost, high-frequency fast charging. More importantly, their thermal reactions are mild during high-rate charging, with a low risk of thermal runaway, significantly improving the operational safety of fast-charging devices.

[0003] In sodium-ion battery systems, the structural control of anode materials plays a crucial role in achieving fast-charging performance. Traditional materials with dense structures and single pore sizes suffer from poor electrolyte permeability, long sodium ion diffusion paths, and limited reaction interfaces, making it difficult to meet the requirements for rapid ion migration and interfacial reaction rates under high-rate operating conditions. In contrast, hierarchical porous structures are considered an important direction for constructing high-performance anode materials due to their excellent mass transfer performance and structural stability. Specifically: macropores can serve as channels for rapid electrolyte permeation, shortening ion transport paths; mesopores buffer volume changes while promoting sodium ion migration; and the synergistic effect of multi-scale channels helps to construct layered and efficient reaction interfaces, improving rate performance and cycle stability. Developing hierarchical porous anode materials with reasonable pore size distribution and spatial connectivity is of great significance for achieving high-rate charge-discharge performance in sodium-ion batteries.

[0004] Among numerous sodium-ion battery anode materials, molybdenum disulfide (MoS2) has attracted considerable attention due to its layered structure, high theoretical capacity, and large interlayer spacing. However, MoS2 is prone to severe volume changes during charge and discharge and exhibits low conductivity, limiting its rate performance and cycle stability. Therefore, a simple and effective strategy is urgently needed for the structural design and control of MoS2 materials to achieve excellent ion transport efficiency, structural stability, and fast-charging performance, thereby promoting the practical application of sodium-ion batteries in the field of fast-charging energy storage. Summary of the Invention

[0005] The purpose of this invention is to provide a three-dimensional hierarchical porous MoS2 material, its preparation method, and its application in fast-charging sodium-ion batteries, thereby solving the problems existing in the prior art. The three-dimensional hierarchical porous MoS2 material of this invention can be applied to fast-charging sodium-ion batteries, exhibiting high rate performance and ultra-long cycle life, thus solving the technical problems of slow sodium ion diffusion and insufficient cycle stability in existing sodium-ion battery technology.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] One of the technical solutions of the present invention is a three-dimensional hierarchical porous MoS2 material, wherein the pore structure of the three-dimensional hierarchical porous MoS2 material includes mesopores and macropores, the mesopores are mainly distributed in the small size range of 2 to 10 nm, and the most probable pore diameter is 2.5 to 4.5 nm;

[0008] The three-dimensional hierarchical porous MoS2 material has a few-layer structure with 1 to 6 layers and an interlayer spacing of 0.68 to 0.71 nm.

[0009] The specific surface area of ​​the three-dimensional hierarchical porous MoS2 material is 40-45 m². 2 / g, pore volume is 0.15~0.25cm³ 3 / g.

[0010] The second technical solution of the present invention: a method for preparing the above-mentioned three-dimensional hierarchical porous MoS2 material, comprising the following steps:

[0011] (1) Add a mixed solution of tetraethyl orthosilicate and cyclohexane to a micelle solution containing an organic quaternary ammonium cation surfactant and triethanolamine, and after the reaction, dendritic mesoporous SiO2 nanospheres are obtained.

[0012] (2) A bimicelle mixture was prepared by combining a molybdenum source, a surfactant containing organic quaternary ammonium cations, and a block copolymer. Then, the dendritic mesoporous SiO2 nanospheres were added, and the mixture was reacted to obtain MoO2. x / SiO2 composite precursor;

[0013] (3) Under an inert atmosphere, the MoO was treated with thiourea. x MoS2 / SiO2 composite material was obtained by confined sulfurization of the / SiO2 composite precursor.

[0014] (4) The MoS2 / SiO2 composite material is dispersed in an alkaline solution and etched to obtain the three-dimensional hierarchical porous MoS2 material.

[0015] Preferably, the surfactant containing an organic quaternary ammonium cation includes one or more of hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, dodecyltrimethylammonium bromide, and octadecyltrimethylammonium bromide.

[0016] Preferably, in step (1), the ratio of the surfactant containing the organic quaternary ammonium cation, triethanolamine, tetraethyl orthosilicate and cyclohexane is 1.5-6 g: 0.4-1.4 mL: 3-6 mL: 15-25 mL;

[0017] Preferably, the triethanolamine is an aqueous solution with a concentration of 0.35 g / mL;

[0018] The reaction time is 12–20 h.

[0019] Preferably, in step (2), the molybdenum source includes ammonium molybdate and / or sodium molybdate;

[0020] The block copolymer includes Pluronic F127;

[0021] The mass ratio of the surfactant containing organic quaternary ammonium cations, the block copolymer, and the dendritic mesoporous SiO2 nanospheres is (0.2–1):(0.2–1):(0.3–0.5).

[0022] The mass ratio of the dendritic mesoporous SiO2 nanospheres to the molybdenum source is 1:(8-25).

[0023] Preferably, in step (3), the MoO x The mass ratio of the SiO2 composite precursor to thiourea is 1:(1-3).

[0024] Preferably, in step (3), the heating rate of the confined vulcanization is 5-10℃ / min, the temperature is 500-800℃, and the time is 2-5h;

[0025] The inert atmosphere is a nitrogen atmosphere and / or an argon atmosphere, and the flow rate is 20-60 mL / min.

[0026] Preferably, in step (4), the alkaline solution includes an aqueous solution of sodium hydroxide;

[0027] The concentration of the sodium hydroxide aqueous solution is 2–4 mol / L;

[0028] The etching process takes 6 to 12 hours.

[0029] This invention utilizes a dendritic mesoporous SiO2 nanosphere hard template and two surfactant micellar soft templates (surfactants containing organic quaternary ammonium cations and block copolymers including Pluronic F127) to synergistically construct a three-dimensional hierarchical porous structure composed of mesopores and macropores. The mesopores are mainly distributed in the small size range of 2–10 nm, with a most probable pore diameter of 2.5–4.5 nm and a specific surface area of ​​40–45 m². 2 / g, pore volume is 0.15~0.25cm³ 3 MoS2 exhibits a few-layer structure (1–6 layers), with the interlayer spacing widened from the theoretical value of 0.62 nm to 0.68–0.71 nm. This significantly improves electrolyte permeability and shortens the sodium ion diffusion path, resulting in excellent fast-charging performance. Furthermore, it effectively mitigates volume expansion and enhances structural stability. As a negative electrode in sodium-ion batteries, this material demonstrates excellent specific capacity, rate performance, and cycle life, showing broad application prospects in fast-charging sodium-ion batteries.

[0030] The third technical solution of the present invention: the application of the above-mentioned three-dimensional hierarchical porous MoS2 material in fast-charging sodium-ion batteries.

[0031] The present invention discloses the following technical effects:

[0032] (1) The three-dimensional hierarchical porous MoS2 material of the present invention can be used to prepare sodium-ion battery anodes with ultra-high rate capability, excellent fast charging performance and cycle stability. At 0.1 A / g, the specific capacity of the first discharge cycle can reach about 620 mAh / g, and the coulombic efficiency is as high as 85.5%; at an ultra-high current density of 20 A / g, the specific capacity is still maintained at about 300 mAh / g; after continuous cycling at 5 A / g for 2500 cycles, the specific capacity is about 350 mAh / g, and the capacity retention rate is 100%; after stable cycling at 20 A / g for 2500 cycles, the capacity is maintained at about 290 mAh / g, and the capacity retention rate is close to 100%, showing excellent ultra-stable fast charging performance.

[0033] (2) Mass transfer and stability of materials with multi-level porous structures:

[0034] This invention introduces a multi-level pore network composed of mesopores and macropores, which effectively shortens the sodium ion diffusion path, reduces diffusion resistance, and enhances the electrochemical response of the material at high rates (high current densities). At the same time, it provides a volume expansion buffer space during sodium ion insertion and extraction, thereby improving the stability of the electrode during cycling.

[0035] (3) Crystal structure regulation promotes rapid ion migration:

[0036] The three-dimensional hierarchical porous MoS2 material prepared by this invention has a crystalline structure, forming a thermodynamically stable pure 2H phase, exhibiting a few-layer structure, and the interlayer spacing is widened from the theoretical value of 0.62 nm to 0.68–0.71 nm, effectively reducing the sodium ion insertion barrier, thereby enhancing the electrochemical kinetic performance of the material.

[0037] (4) Template-based collaborative regulation to construct high-quality multi-level porous networks:

[0038] Traditional single-template systems are difficult to construct multi-scale porous structures. This invention uses dendritic mesoporous SiO2 nanosphere hard templates and two types of surfactants (surfactants containing organic quaternary ammonium cations and block copolymers including Pluronic F127) to form micelle soft templates of different sizes, which promote the formation of a three-dimensional multi-level porous network with a wide pore size distribution, good connectivity and orderly structure, so as to achieve precise control of multi-level channels. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 Scanning electron microscope image of the SiO2 nanospheres with dendritic mesoporous structure prepared in Example 1;

[0041] Figure 2 Scanning electron microscope images of three-dimensional hierarchical porous MoS2 material 1 prepared in Example 1, three-dimensional hierarchical porous MoS2 material 2 prepared in Example 2, and three-dimensional hierarchical porous MoS2 material 3 prepared in Example 3, wherein (a) is Example 1, (b) is Example 2, and (c) is Example 3;

[0042] Figure 3 Scanning electron microscope images of MoS2 comparative material 1 prepared for Comparative Example 1, MoS2 comparative material 2 prepared for Comparative Example 2, and MoS2 comparative material 3 prepared for Comparative Example 3, wherein (a) is Comparative Example 1, (b) is Comparative Example 2, and (c) is Comparative Example 3.

[0043] Figure 4 The image shows a transmission electron microscope (TEM) image of the three-dimensional hierarchical porous MoS2 material 2 prepared in Example 2, where (a) and (b) are TEM images at different magnifications.

[0044] Figure 5 X-ray diffraction patterns of three-dimensional hierarchical porous MoS2 material 1 prepared in Example 1, three-dimensional hierarchical porous MoS2 material 2 prepared in Example 2, and three-dimensional hierarchical porous MoS2 material 3 prepared in Example 3;

[0045] Figure 6 Raman spectra of three-dimensional hierarchical porous MoS2 material 1 prepared in Example 1, three-dimensional hierarchical porous MoS2 material 2 prepared in Example 2, and three-dimensional hierarchical porous MoS2 material 3 prepared in Example 3;

[0046] Figure 7 The nitrogen adsorption-desorption curves and pore size distribution curves of the three-dimensional hierarchical porous MoS2 material 1 prepared in Example 1, the three-dimensional hierarchical porous MoS2 material 2 prepared in Example 2, and the three-dimensional hierarchical porous MoS2 material 3 prepared in Example 3 are shown. (a) is the nitrogen adsorption-desorption curve, and (b) is the pore size distribution curve.

[0047] Figure 8 The nitrogen adsorption-desorption curves and pore size distribution curves of MoS2 comparative material 1 prepared in Comparative Example 1, MoS2 comparative material 2 prepared in Comparative Example 2, and MoS2 comparative material 3 prepared in Comparative Example 3 are shown. (a) is the nitrogen adsorption-desorption curve, and (b) is the pore size distribution curve.

[0048] Figure 9 The constant current charge-discharge performance curves of the three-dimensional hierarchical porous MoS2 materials prepared in Examples 1 to 3 at a current density of 0.1 A / g for the first three cycles are shown. (a) is Example 1, (b) is Example 2, and (c) is Example 3.

[0049] Figure 10 The graphs show the rate performance of the three-dimensional hierarchical porous MoS2 materials prepared in Examples 1-3 and the MoS2 materials prepared in Comparative Examples 1-3, where (a) represents Examples 1-3 and (b) represents Comparative Examples 1-3.

[0050] Figure 11 The graph shows the cycling performance of the three-dimensional hierarchical porous MoS2 materials prepared in Examples 1-3 at a current density of 5 A / g.

[0051] Figure 12 The graph shows the cycling performance of the three-dimensional hierarchical porous MoS2 materials prepared in Examples 1-3 at a current density of 20 A / g.

[0052] Figure 13 The images show scanning electron microscope (SEM) images of the three-dimensional hierarchical porous MoS2 material 2 prepared in Example 2 before and after charge-discharge cycles. In the images, (a) is the original electrode sheet before cycling, (b) is the electrode sheet after 1 cycle at 0.1 A / g, (c) is the electrode sheet after 500 cycles at 5 A / g, and (d) is the electrode sheet after 1000 cycles at 5 A / g. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] In the following description, references to "some embodiments" refer to a subset of all possible embodiments; however, it is understood that "some embodiments" may be the same or different subsets of all possible embodiments and may be combined with each other without conflict. Unless otherwise defined, all technical and scientific terms used in the embodiments of the invention have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments of the invention pertain. The terminology used in the embodiments of the invention is for the purpose of describing the embodiments of the invention only and is not intended to limit the invention.

[0055] In the following description of this embodiment, the terms "including", "comprising", "having", and "containing" are all open-ended terms, meaning that they include but are not limited to.

[0056] It should be noted that all raw materials / reagents in the embodiments of the present invention can be purchased on the market or prepared according to conventional methods known to those skilled in the art; the term "and / or" in the embodiments of the present invention is only used to describe the relationship between related objects, indicating that there can be three relationships. For example, A and / or B means three cases: A exists alone, B exists alone, and A and B exist simultaneously. A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship.

[0057] In the following description of this embodiment, the term "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0058] Those skilled in the art should understand that, in the following description of the embodiments of the present invention, the sequence of numbers does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0059] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0060] Those skilled in the art will understand that the numerical ranges in the embodiments of the present invention should be understood as each intermediate value between the upper and lower limits of the specifically disclosed range. Each smaller range between any stated value and an intermediate value within the stated range, as well as any other stated value or an intermediate value within the stated range, is also included within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0061] Unless otherwise stated, the technical / scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art.

[0062] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0063] In a first aspect, this invention provides a three-dimensional hierarchical porous MoS2 material. This material has a crystalline structure (with good crystallinity), is a thermodynamically stable pure 2H phase, exhibits a few-layer structure (1-6 layers), and the interlayer spacing is broadened from the theoretical value of 0.62 nm to 0.68-0.71 nm. It possesses a finely constructed three-dimensional hierarchical porous structure, composed of both mesopores and macropores. The mesopores are mainly distributed in the small size range of 2-10 nm, with a most probable pore diameter of 2.5-4.5 nm. The specific surface area of ​​this material is 40-45 m². 2 / g, pore volume is 0.15~0.25cm³ 3 / g.

[0064] The increased interlayer spacing of the three-dimensional hierarchical porous MoS2 material of this invention is beneficial for constructing wider ion diffusion channels.

[0065] The structural characteristics of the three-dimensional hierarchical porous MoS2 material of the present invention can provide an ideal interfacial environment for ion transport and electrolyte wetting.

[0066] In a second aspect, the present invention provides a method for preparing a three-dimensional hierarchical porous MoS2 material, comprising the following steps:

[0067] (1) Add a surfactant containing an organic quaternary ammonium cation and triethanolamine (TEA) together to water and disperse them uniformly to obtain a micelle solution (i.e., an aqueous solution);

[0068] Tetraethyl orthosilicate (TEOS) and cyclohexane were mixed evenly to obtain an organic phase mixed solution;

[0069] An organic phase mixture was slowly added to a micelle solution (i.e., an aqueous solution), and the reaction was carried out under continuous stirring. Impurities were removed by washing, centrifugation, and other steps to obtain dendritic mesoporous SiO2 nanospheres.

[0070] (2) Add molybdenum source, surfactant containing organic quaternary ammonium cation and block copolymer to water, and disperse by ultrasonication to obtain a micelle mixture;

[0071] Dendritic mesoporous SiO2 nanospheres prepared above were added to a micelle mixture, subjected to ultrasonic reaction, and then dried after vacuum filtration to obtain MoO2. x / SiO2 composite precursor.

[0072] (3) Under an inert atmosphere, thiourea was used to treat the aforementioned MoO. x MoS2 / SiO2 composite material was obtained by gas-phase confined sulfidation treatment of the / SiO2 composite precursor.

[0073] (4) The aforementioned MoS2 / SiO2 composite material was dispersed in an aqueous sodium hydroxide solution for etching treatment. After washing and separation, a three-dimensional hierarchical porous MoS2 material was obtained.

[0074] Preferably, the surfactant containing an organic quaternary ammonium cation includes one or more of hexadecyltrimethylammonium bromide (CTAB), hexadecyltrimethylammonium chloride (CTAC), dodecyltrimethylammonium bromide (DTAB), and octadecyltrimethylammonium bromide (OTAB), more preferably CTAB.

[0075] Preferably, in step (1), the ratio of the surfactant containing the organic quaternary ammonium cation, triethanolamine, tetraethyl orthosilicate and cyclohexane is 1.5-6 g: 0.4-1.4 mL: 3-6 mL: 15-25 mL;

[0076] Preferably, the triethanolamine is an aqueous solution with a concentration of 0.35 g / mL;

[0077] The reaction time is 12–20 hours.

[0078] It should be noted that in this process, a surfactant containing an organic quaternary ammonium cation acts as a micelle soft template to guide the hydrolysis-assembly process of tetraethyl orthosilicate in order to form dendritic mesoporous SiO2 nanospheres. By controlling its amount within this range, uniform nanosphere diameter and dendritic mesoporous structure can be achieved.

[0079] Preferably, in step (2), the molybdenum source includes ammonium molybdate and / or sodium molybdate, more preferably ammonium molybdate.

[0080] Block copolymers include Pluronic F127;

[0081] The mass ratio of surfactant containing organic quaternary ammonium cations, block copolymers, and dendritic mesoporous SiO2 nanospheres is (0.2–1):(0.2–1):(0.3–0.5).

[0082] The mass ratio of dendritic mesoporous SiO2 nanospheres to molybdenum source is 1:(8-25).

[0083] It should be noted that, in this process, the surfactant containing organic quaternary ammonium cations forms micelle template 1 in aqueous solution. Through the electrostatic interaction between the quaternary ammonium cation groups and molybdate anions, the molybdenum source is induced to assemble uniformly on the surface of the SiO2 nanosphere hard template, forming mesoporous structure 1 in the final MoS2 material. The block copolymer F127 forms micelle template 2 in aqueous solution. Its size and properties are different from those of micelle template 1. It mainly binds the molybdenum source through the oxygen-containing groups at its hydrophilic end, forming mesoporous structure 2 in the final MoS2 material. The two of them work synergistically with the mesoporous SiO2 nanosphere hard template to control the assembly process of the reaction precursor and realize the construction of a three-dimensional hierarchical porous structure.

[0084] Preferably, in step (3), MoO x The mass ratio of the SiO2 composite precursor to thiourea is 1:(1-3).

[0085] Preferably, in step (3), the heating rate of the gas-phase confined sulfidation treatment is 5-10℃ / min, the temperature is 500-800℃, and the time is 2-5h;

[0086] The inert atmosphere is nitrogen and / or argon, and the flow rate is 20–60 mL / min.

[0087] Preferably, in step (4), the concentration of the sodium hydroxide aqueous solution is 2-4 mol / L;

[0088] The etching process takes 6 to 12 hours.

[0089] The three-dimensional hierarchical porous MoS2 material prepared by the method of this invention has a crystalline structure, forming a thermodynamically stable pure 2H phase, exhibiting a few-layer structure (1 to 6 layers), and the interlayer spacing is broadened from the theoretical value of 0.62 nm to 0.68 to 0.71 nm; it has a three-dimensional hierarchical porous structure, composed of both mesopores and macropores, with mesopores mainly distributed in the small size range of 2 to 10 nm, and the most probable pore diameter being 2.5 to 4.5 nm; the specific surface area of ​​the three-dimensional hierarchical porous MoS2 material is 40 to 45 m². 2 / g, pore volume is 0.15~0.25cm³ 3 / g.

[0090] In a third aspect, the present invention provides an application of the above-mentioned three-dimensional hierarchical porous MoS2 material in a fast-charging sodium-ion battery.

[0091] The anode material prepared using three-dimensional hierarchical porous MoS2 material has a fast sodium ion diffusion path, excellent rate performance, long-term cycling stability, and still has a high capacity retention rate under high power conditions.

[0092] All raw materials and reagents in the embodiments of this invention were purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0093] Example 1

[0094] A method for preparing three-dimensional hierarchical porous MoS2 materials:

[0095] (1) Mix 6 mL of tetraethyl orthosilicate (TEOS) and 16 mL of cyclohexane evenly to obtain an organic phase mixed solution;

[0096] Add 6g CTAB and 0.75mL TEA to 60mL of deionized water, stir to form a homogeneous and transparent solution, and heat to 60℃ and stir for 30 minutes to obtain a micelle solution (i.e., an aqueous solution). Then, slowly add a pre-prepared organic phase mixture to the micelle solution (i.e., the aqueous solution), and continue stirring for about 12 hours to allow the SiO2 framework to gradually assemble. After the reaction is complete, add an appropriate amount of anhydrous ethanol to wash and purify the system, collect the product by centrifugation, and dry the product to obtain SiO2 nanospheres with a dendritic mesoporous structure.

[0097] (2) 4.98 g of ammonium molybdate, 0.5 g of CTAB, and 0.3 g of block copolymer Pluronic F127 were added to 28 mL of deionized water and sonicated to form a uniformly dispersed precursor solution. 0.3 g of the aforementioned SiO2 nanospheres with a dendritic mesoporous structure were added to the precursor solution, and the mixture was further sonicated to achieve uniform dispersion. After vacuum filtration, the resulting solid was dried to obtain MoO2. x / SiO2 composite precursor.

[0098] (3) Add 0.6g MoO x The SiO2 composite precursor and 1.2g of thiourea were placed in two corundum boats, with the thiourea placed upstream of the tube furnace as a sulfur source, and MoO2... x The MoS2 / SiO2 composite precursor was placed in the downstream reaction region; high-purity argon gas was introduced at a rate of 40 mL / min to establish a protective atmosphere, and then the temperature was increased to 700 °C at a rate of 10 °C / min and held for 2 hours for gas-phase confined sulfidation treatment. After natural cooling to room temperature, the MoS2 / SiO2 composite material was obtained.

[0099] (4) The aforementioned MoS2 / SiO2 composite material was dispersed in a 3 mol / L sodium hydroxide aqueous solution and etched for 10 h. After washing and separation, a three-dimensional hierarchical porous MoS2 material 1 was obtained.

[0100] Example 2

[0101] A method for preparing three-dimensional hierarchical porous MoS2 materials:

[0102] (1) Mix 6 mL of tetraethyl orthosilicate (TEOS) and 16 mL of cyclohexane evenly to obtain an organic phase mixed solution;

[0103] Add 6g CTAB and 0.75mL TEA to 60mL of deionized water, stir to form a homogeneous and transparent solution, and heat to 60℃ and stir for 30 minutes to obtain a micelle solution (i.e., an aqueous solution). Then, slowly add a pre-prepared organic phase mixture to the micelle solution (i.e., the aqueous solution), and continue stirring for about 12 hours to allow the SiO2 framework to gradually assemble. After the reaction is complete, add an appropriate amount of anhydrous ethanol to wash and purify the system, collect the product by centrifugation, and dry the obtained precipitate to obtain SiO2 nanospheres with a dendritic mesoporous structure.

[0104] (2) 4.98 g of ammonium molybdate, 0.5 g of CTAB, and 0.5 g of block copolymer Pluronic F127 were added to 28 mL of deionized water and sonicated to form a uniformly dispersed precursor solution. 0.3 g of the aforementioned SiO2 nanospheres with a dendritic mesoporous structure were added to the precursor solution, and the mixture was further sonicated to achieve uniform dispersion. After vacuum filtration, the resulting solid was dried to obtain MoO2. x / SiO2 composite precursor.

[0105] (3) Add 0.6g MoO x The SiO2 composite precursor and 1.2g of thiourea were placed in two corundum boats, with the thiourea placed upstream of the tube furnace as a sulfur source, and MoO2... x The MoS2 / SiO2 composite precursor was placed in the downstream reaction region; high-purity argon gas was introduced at a rate of 40 mL / min to establish a protective atmosphere, and then the temperature was increased to 700 °C at a rate of 10 °C / min and held for 2 hours for gas-phase confined sulfidation treatment. After natural cooling to room temperature, the MoS2 / SiO2 composite material was obtained.

[0106] (4) The aforementioned MoS2 / SiO2 composite material was dispersed in a 3 mol / L sodium hydroxide aqueous solution for etching treatment for 10 h. After washing and separation, a three-dimensional hierarchical porous MoS2 material 2 was obtained.

[0107] Example 3

[0108] A method for preparing three-dimensional hierarchical porous MoS2 materials:

[0109] (1) Mix 6 mL of tetraethyl orthosilicate (TEOS) and 16 mL of cyclohexane evenly to obtain an organic phase mixed solution;

[0110] Add 6g CTAB and 0.75mL TEA to 60mL of deionized water, stir to form a homogeneous and transparent solution, and heat to 60℃ and stir for 30 minutes to obtain a micelle solution (i.e., an aqueous solution). Then, slowly add a pre-prepared organic phase mixture to the micelle solution (i.e., the aqueous solution), and continue stirring for about 12 hours to allow the SiO2 framework to gradually assemble. After the reaction is complete, add an appropriate amount of anhydrous ethanol to wash and purify the system, collect the product by centrifugation, and dry the obtained precipitate to obtain SiO2 nanospheres with a dendritic mesoporous structure.

[0111] (2) 4.98 g of ammonium molybdate, 0.5 g of CTAB, and 0.7 g of block copolymer Pluronic F127 were added to 28 mL of deionized water and sonicated to form a uniformly dispersed precursor solution. 0.3 g of the aforementioned SiO2 nanospheres with a dendritic mesoporous structure were added to the precursor solution, and the mixture was further sonicated to achieve uniform dispersion. After vacuum filtration, the resulting solid was dried to obtain MoO2. x / SiO2 composite precursor.

[0112] (3) Add 0.6g MoO x The SiO2 composite precursor and 1.2g of thiourea were placed in two corundum boats, with the thiourea placed upstream of the tube furnace as a sulfur source, and MoO2... x The MoS2 / SiO2 composite precursor was placed in the downstream reaction region; high-purity argon gas was introduced at a rate of 40 mL / min to establish a protective atmosphere, and then the temperature was increased to 700 °C at a rate of 10 °C / min and held for 2 hours for gas-phase confined sulfidation treatment. After natural cooling to room temperature, the MoS2 / SiO2 composite material was obtained.

[0113] (4) The aforementioned MoS2 / SiO2 composite material was dispersed in a 3 mol / L sodium hydroxide aqueous solution for etching treatment for 10 h. After washing and separation, a three-dimensional hierarchical porous MoS2 material 3 was obtained.

[0114] Comparative Example 1

[0115] A method for preparing MoS2 comparative material 1:

[0116] (1) Add 4.98g ammonium molybdate, 0.5g CTAB and 0.5g block copolymer Pluronic F127 to 28mL of deionized water, sonicate to form a uniformly dispersed precursor solution, filter under vacuum and dry to obtain MoO x Precursor.

[0117] (2) Add 0.6g MoO x The precursor and 1.2 g of thiourea were placed in two separate corundum boats, with the thiourea positioned upstream of the tube furnace as a sulfur source. MoO x / SiO2 was placed in the downstream reaction region; high-purity argon was introduced at a rate of 40 mL / min to establish a protective atmosphere, and then the temperature was increased to 700℃ at a rate of 10℃ / min and held for 2 hours for gas-phase confined sulfidation treatment. After natural cooling to room temperature, MoS2 comparative material 1 was obtained.

[0118] Comparative Example 2

[0119] A method for preparing MoS2 contrast material 2:

[0120] (1) Mix 6 mL of tetraethyl orthosilicate (TEOS) and 16 mL of cyclohexane evenly to obtain an organic phase mixed solution;

[0121] Add 6g CTAB and 0.75mL TEA to 60mL of deionized water, stir to form a homogeneous and transparent solution, and heat to 60℃ and stir for 30 minutes to obtain a micelle solution (i.e., an aqueous solution). Then, slowly add a pre-prepared organic phase mixture to the micelle solution (i.e., the aqueous solution) and continue stirring for about 12 hours to allow the SiO2 framework to gradually assemble. After the reaction is complete, add an appropriate amount of anhydrous ethanol to treat and wash the system for purification, and collect the product by centrifugation. Dry the obtained precipitate to obtain SiO2 nanospheres with a dendritic mesoporous structure.

[0122] (2) 4.98 g of ammonium molybdate and 0.5 g of block copolymer Pluronic F127 were added to 28 mL of deionized water and sonicated to form a uniformly dispersed precursor solution. 0.3 g of the aforementioned SiO2 nanospheres with a dendritic mesoporous structure were added to the precursor solution, and the mixture was further sonicated to achieve uniform dispersion. After vacuum filtration, the resulting solid was dried to obtain MoO2. x / SiO2 composite precursor.

[0123] (3) Add 0.6g MoO x The SiO2 composite precursor and 1.2g of thiourea were placed in two corundum boats, with the thiourea placed upstream of the tube furnace as a sulfur source, and MoO2... xThe MoS2 / SiO2 composite precursor was placed in the downstream reaction region; high-purity argon gas was introduced at a rate of 40 mL / min to establish a protective atmosphere, and then the temperature was increased to 700 °C at a rate of 10 °C / min and held for 2 hours for gas-phase confined sulfidation treatment. After natural cooling to room temperature, the MoS2 / SiO2 composite material was obtained.

[0124] (4) The aforementioned MoS2 / SiO2 composite material was dispersed in a 3 mol / L sodium hydroxide aqueous solution and etched for 10 h. After washing and separation, MoS2 comparative material 2 was obtained.

[0125] Comparative Example 3

[0126] A method for preparing MoS2 contrast material 3:

[0127] (1) Mix 6 mL of tetraethyl orthosilicate (TEOS) and 16 mL of cyclohexane evenly to obtain an organic phase mixed solution;

[0128] Add 6g CTAB and 0.75mL TEA to 60mL of deionized water, stir to form a homogeneous and transparent solution, and heat to 60℃ and stir for 30 minutes to obtain a micelle solution (i.e., an aqueous solution). Then, slowly add a pre-prepared organic phase mixture to the micelle solution (i.e., the aqueous solution), and continue stirring for about 12 hours to allow the SiO2 framework to gradually assemble. After the reaction is complete, add an appropriate amount of anhydrous ethanol to wash and purify the system, collect the product by centrifugation, and dry the obtained precipitate to obtain SiO2 nanospheres with a dendritic mesoporous structure.

[0129] (2) 4.98 g of ammonium molybdate and 0.5 g of CTAB were added to 28 mL of deionized water and sonicated to form a uniformly dispersed precursor solution. 0.3 g of the aforementioned SiO2 nanospheres with a dendritic mesoporous structure were added to the precursor solution, and the mixture was further sonicated to achieve uniform dispersion. After vacuum filtration, the resulting solid was dried to obtain MoO2. x / SiO2 composite precursor.

[0130] (3) Add 0.6g MoO x The SiO2 composite precursor and 1.2g of thiourea were placed in two corundum boats, with the thiourea placed upstream of the tube furnace as a sulfur source, and MoO2... x The MoS2 / SiO2 composite precursor was placed in the downstream reaction region; high-purity argon gas was introduced at a rate of 40 mL / min to establish a protective atmosphere, and then the temperature was increased to 700 °C at a rate of 10 °C / min and held for 2 hours for gas-phase confined sulfidation treatment. After natural cooling to room temperature, the MoS2 / SiO2 composite material was obtained.

[0131] (4) The aforementioned MoS2 / SiO2 composite material was dispersed in a 3 mol / L sodium hydroxide aqueous solution and etched for 10 h. After washing and separation, MoS2 comparative material 3 was obtained.

[0132] Example 1

[0133] (1) Scanning electron microscope image of the SiO2 nanospheres with dendritic mesoporous structure prepared in Example 1 is shown in [reference needed]. Figure 1 .

[0134] from Figure 1 As can be seen, the SiO2 particles prepared by this invention are generally regular spherical with a relatively uniform particle size distribution of about 120 nm; they have significant dendritic mesoporous channels that are interconnected.

[0135] (2) Scanning electron microscope images of three-dimensional hierarchical porous MoS2 material 1 prepared in Example 1, three-dimensional hierarchical porous MoS2 material 2 prepared in Example 2, and three-dimensional hierarchical porous MoS2 material 3 prepared in Example 3 are shown below. Figure 2 , Figure 2 In the examples, (a) is Example 1, (b) is Example 2, and (c) is Example 3.

[0136] from Figure 2 As can be seen from the data, the three-dimensional hierarchical porous MoS2 materials prepared in Examples 1-3 exhibit a distinct pore structure and layered wrinkles on their surface, possessing a relatively complete three-dimensional hierarchical pore network. This structure not only effectively increases the specific surface area and pore volume of the material, facilitating electrolyte penetration and ion diffusion, but also alleviates volumetric strain during charge and discharge processes, thereby improving cycle stability.

[0137] (3) Scanning electron microscope images of MoS2 comparative material 1 prepared in Comparative Example 1, MoS2 comparative material 2 prepared in Comparative Example 2, and MoS2 comparative material 3 prepared in Comparative Example 3 are shown below. Figure 3 , Figure 3 In the examples, (a) is Comparative Example 1, (b) is Comparative Example 2, and (c) is Comparative Example 3.

[0138] from Figure 3 As can be seen from the data, the MoS2 materials prepared in Comparative Examples 1 to 3 mainly exhibit a disordered aggregated state, with pores primarily originating from the gaps between particles. The overall structure is loose, lacking continuous conductive channels and a stable porous framework. This indicates that the three elements of the hard template of SiO2 nanospheres with dendritic mesoporous structure, CTAB, and F127 micelle soft template are all crucial for the formation of a three-dimensional hierarchical porous structure, and none of them can be omitted.

[0139] (4) The transmission electron microscope image of the three-dimensional hierarchical porous MoS2 material 2 prepared in Example 2 is shown below. Figure 4 , Figure 4(a) and (b) are transmission electron microscope images at different magnifications.

[0140] from Figure 4 As can be seen from the data, the microstructure of the three-dimensional hierarchical porous MoS2 material 2 prepared in Example 2 exhibits hierarchical channels with a synergistic distribution of mesopores and macropores, which can significantly improve the accessibility of ion transport channels and the utilization rate of the reaction interface. Furthermore, this material has a few-layer structure, with the interlayer spacing represented by its (002) crystal plane widened to 0.696 nm, significantly larger than the 0.62 nm of the conventional MoS2 structure, which can accommodate Na… + Reversible intercalation provides a wider channel.

[0141] (5) The X-ray diffraction patterns of the three-dimensional hierarchical porous MoS2 material 1 prepared in Example 1, the three-dimensional hierarchical porous MoS2 material 2 prepared in Example 2, and the three-dimensional hierarchical porous MoS2 material 3 prepared in Example 3 are shown in the figure. Figure 5 .

[0142] from Figure 5 As can be seen from the data, the three-dimensional hierarchical porous MoS2 materials prepared in Examples 1-3 all exhibit typical (002), (100), (103), and (110) diffraction peaks of the 2H phase MoS2. Among them, the (002) peak is significantly shifted to the left, with increased peak width and decreased intensity, indicating a significant widening of the MoS2 interlayer spacing. According to Bragg's formula, the (002) interlayer spacing of the three-dimensional hierarchical porous MoS2 material is widened from the theoretical value of 0.62 nm to 0.68-0.71 nm, which will help promote the Na+... + The insertion and extraction of these molecules enhance electrochemical performance.

[0143] (6) The Raman spectra of the three-dimensional hierarchical porous MoS2 material 1 prepared in Example 1, the three-dimensional hierarchical porous MoS2 material 2 prepared in Example 2, and the three-dimensional hierarchical porous MoS2 material 3 prepared in Example 3 are shown below. Figure 6 .

[0144] from Figure 6 As can be seen from the data, the three-dimensional hierarchical porous MoS2 materials prepared in Examples 1-3 possess a typical 2H phase MoS2 structure, with two characteristic peaks located at approximately 378 cm⁻¹. -1 and 401cm -1 At each location, corresponding to its in-plane (E) 1 2g ) and interlayer (A 1g Vibration mode. The peak position difference between the two peaks is approximately 23.1 cm. -1 Significantly lower than bulk MoS2 (approximately 25 cm³). -1 This indicates that it has fewer layers or weaker interlayer forces, which will further benefit Na. + Rapid intercalation and diffusion.

[0145] (7) The nitrogen adsorption-desorption curves and pore size distribution curves of the three-dimensional hierarchical porous MoS2 material 1 prepared in Example 1, the three-dimensional hierarchical porous MoS2 material 2 prepared in Example 2, and the three-dimensional hierarchical porous MoS2 material 3 prepared in Example 3 are shown in the figure. Figure 7 , Figure 7 In the figure, (a) is the nitrogen adsorption-desorption curve, and (b) is the pore size distribution curve.

[0146] from Figure 7 As can be seen, the three-dimensional hierarchical porous MoS2 materials prepared in Examples 1-3 all exhibit typical mesoporous characteristics, with most probable pore sizes of 2.5-4.5 nm, accompanied by a certain number of macropores (where the size of small mesopores is 2-10 nm, the size of large mesopores is 10-50 nm, and the size of macropores is >50 nm), confirming the existence of their hierarchical pore structure. The specific surface area of ​​the three-dimensional hierarchical porous MoS2 materials prepared in Examples 1-3 is 40-45 m². 2 / g, pore volume is 0.15~0.25m³ 3 / g (see Table 1).

[0147] (8) The nitrogen adsorption-desorption curves and pore size distribution curves of MoS2 comparative material 1 prepared in Comparative Example 1, MoS2 comparative material 2 prepared in Comparative Example 2, and MoS2 comparative material 3 prepared in Comparative Example 3 are shown in the figure. Figure 8 , Figure 8 In the figure, (a) is the nitrogen adsorption-desorption curve, and (b) is the pore size distribution curve.

[0148] from Figure 8 As can be seen from the data, the specific surface areas of the MoS2 materials prepared in Comparative Examples 1–3 were 4.5 m², respectively. 2 / g, 26.5m 2 / g and 23.7m 2 / g, pore volume not exceeding 0.05m³ 3 / g (see Table 1) were significantly lower than those of the MoS2 materials prepared in Examples 1-3, further indicating that the MoS2 materials prepared in Examples 1-3 lacked an effective hierarchical pore structure, making it difficult to achieve good electrolyte wettability and rapid ion transport.

[0149] Table 1. Pore structure parameters of MoS2 materials prepared in Examples 1-3 and Comparative Examples 1-3

[0150]

[0151] Application Example 1

[0152] Sodium-ion battery anode and preparation method of battery assembled using sodium-ion battery anode:

[0153] (1) Preparation of sodium-ion battery anode: MoS2 material (three-dimensional hierarchical porous MoS2 material 1 prepared in Example 1, three-dimensional hierarchical porous MoS2 material 2 prepared in Example 2, three-dimensional hierarchical porous MoS2 material 3 prepared in Example 3, MoS2 comparative material 1 prepared in Comparative Example 1, MoS2 comparative material 2 prepared in Comparative Example 2, or MoS2 comparative material 3 prepared in Comparative Example 3), conductive carbon black (Super P) and polyvinylidene fluoride (PVDF) were mixed in a mass ratio of 7:2:1. An appropriate amount of N-methylpyrrolidone (NMP) was slowly added as a dispersant, and the mixture was thoroughly ground in a mortar until a uniform and viscous black slurry was formed. The slurry was then uniformly coated on the surface of a copper foil current collector and placed in a vacuum drying oven to dry overnight at 80°C to obtain a dried electrode sheet (i.e., sodium-ion battery anode, with a MoS2 material loading of 1.1–1.3 mg / cm³). 2 ).

[0154] (2) Battery fabrication: CR2032 semi-button batteries were assembled in a glove box filled with high-purity argon gas. Dry electrode sheets (i.e., the negative electrode of a sodium-ion battery) were used as the working electrode, a metallic sodium sheet as the counter electrode, and a glass fiber membrane as the separator. A dimethyl ether (DME) solution containing 1 mol / L sodium hexafluorophosphate (NaPF6) was used as the electrolyte. The assembled battery was allowed to stand at room temperature for 8 hours to ensure the electrolyte fully wetted the electrode-separator interface. The constant current charge-discharge test voltage range was 0.01–3V (vs. NaPF6). + / Na).

[0155] (3) The constant current charge-discharge performance curves of the three-dimensional hierarchical porous MoS2 materials prepared in Examples 1-3 were measured at a current density of 0.1 A / g for the first three cycles. The results are shown in the figure. Figure 9 , Figure 9 In the examples, (a) is Example 1, (b) is Example 2, and (c) is Example 3.

[0156] from Figure 9 As can be seen in Figure (a), the three-dimensional hierarchical porous MoS2 material 1 prepared in Example 1 has a first-cycle discharge specific capacity of 627.8 mAh / g, a charge specific capacity of 487.2 mAh / g, and a coulombic efficiency of 77.6%. Figure 9 As can be seen in Figure (b), the three-dimensional hierarchical porous MoS2 material 2 prepared in Example 2 has a first-cycle discharge specific capacity of 624.0 mAh / g, a charge specific capacity of 533.5 mAh / g, and a coulombic efficiency of 85.5%. Figure 9As shown in Figure (c), the three-dimensional hierarchical porous MoS2 material 3 prepared in Example 3 has a first-cycle discharge specific capacity of 615.8 mAh / g, a charge specific capacity of 456.3 mAh / g, and a coulombic efficiency of 74.1%. These results indicate that the three-dimensional hierarchical porous structure significantly improves the reversible specific capacity and initial coulombic efficiency of the MoS2 material, especially Example 2, which demonstrates superior performance, indicating that its pore structure and interlayer spacing are well-controlled.

[0157] (4) The rate performance diagrams of the three-dimensional hierarchical porous MoS2 materials prepared in Examples 1-3 and the MoS2 materials prepared in Comparative Examples 1-3 are shown in the figure. Figure 10 , Figure 10 In the examples, (a) represents Examples 1 to 3, and (b) represents Comparative Examples 1 to 3.

[0158] from Figure 10 As can be seen from the results, the three-dimensional hierarchical porous MoS2 materials prepared in Examples 1 to 3 exhibit excellent rate performance in a wide current density range from 0.1 to 20 A / g. In particular, they can maintain a high specific capacity at high rates, demonstrating extremely excellent fast charging potential.

[0159] from Figure 10 As shown in Figure (a), the specific capacities of the three-dimensional hierarchical porous MoS2 material 1 prepared in Example 1 at current densities of 0.1 A / g, 0.2 A / g, 0.5 A / g, 1 A / g, 2 A / g, 5 A / g, 10 A / g, and 20 A / g are 489.0 mAh / g, 414.5 mAh / g, 395.0 mAh / g, 372.5 mAh / g, 354.3 mAh / g, 331.1 mAh / g, 331.4 mAh / g, and 289.5 mAh / g, respectively; and the specific capacities of the three-dimensional hierarchical porous MoS2 material 2 prepared in Example 2 at current densities of 0.1 A / g, 0.2 A / g, 0.5 A / g, 1 A / g, 2 A / g, 5 A / g, 10 A / g, and 20 A / g are 5... The specific capacities of the three-dimensional hierarchical porous MoS2 material 3 prepared in Example 3 at current densities of 0.1 A / g, 0.2 A / g, 0.5 A / g, 1 A / g, 2 A / g, 5 A / g, 10 A / g, and 20 A / g were 457.1 mAh / g, 384.5 mAh / g, 379.4 mAh / g, 367.0 mAh / g, 354.1 mAh / g, 336.5 mAh / g, 319.2 mAh / g, and 300.6 mAh / g, respectively (see Table 2).

[0160] from Figure 10As shown in Figure (b), the specific capacity of the MoS2 materials prepared in Comparative Examples 1-3 decreased significantly at high current densities. The specific capacities of MoS2 material 1 prepared in Comparative Example 1 at current densities of 0.1 A / g, 0.2 A / g, 0.5 A / g, 1 A / g, 2 A / g, 5 A / g, 10 A / g, and 20 A / g were 404.0 mAh / g, 361.2 mAh / g, 342.4 mAh / g, 325.0 mAh / g, 293.6 mAh / g, 229.1 mAh / g, 180.6 mAh / g, and 136.1 mAh / g, respectively. The specific capacities of MoS2 material 2 prepared in Comparative Example 2 at current densities of 0.1 A / g, 0.2 A / g, 0.5 A / g, 1 A / g, 2 A / g, 5 A / g, 10 A / g, and 20 A / g were 404.0 mAh / g, 361.2 mAh / g, 342.4 mAh / g, 325.0 mAh / g, 293.6 mAh / g, 229.1 mAh / g, 180.6 mAh / g, and 136.1 mAh / g, respectively. The specific capacities at 0 A / g were 384.0 mAh / g, 334.2 mAh / g, 303.4 mAh / g, 274.2 mAh / g, 240.5 mAh / g, 191.6 mAh / g, 156.1 mAh / g, and 121.7 mAh / g, respectively. The specific capacities of MoS2 material 3 prepared in Comparative Example 3 at current densities of 0.1 A / g, 0.2 A / g, 0.5 A / g, 1 A / g, 2 A / g, 5 A / g, 10 A / g, and 20 A / g were 389.6 mAh / g, 325.2 mAh / g, 291.5 mAh / g, 271.7 mAh / g, 248.4 mAh / g, 203.3 mAh / g, 160.6 mAh / g, and 116.7 mAh / g, respectively (see Table 2).

[0161] Table 2. Discharge specific capacity of MoS2 materials prepared in Examples 1-3 and Comparative Examples 1-3 at different current densities (unit: mAh / g)

[0162] <![CDATA[MoS2 material]]> 0.1A / g 0.2A / g 0.5A / g 1A / g 2A / g 5A / g 10A / g 20A / g Example 1 489.0 414.5 395.0 372.5 354.3 331.1 331.4 289.5 Example 2 520.8 395.8 396.1 382.3 365.4 343.2 320.0 295.6 Example 3 457.1 384.5 379.4 367.0 354.1 336.5 319.2 300.6 Comparative Example 1 404.0 361.2 342.4 325.0 293.6 229.1 180.6 136.1 Comparative Example 2 384.0 334.2 303.4 274.2 240.5 191.6 156.1 121.7 Comparative Example 3 389.6 325.2 291.5 271.7 248.4 203.3 160.6 116.7

[0163] (5) The cycling performance of the three-dimensional hierarchical porous MoS2 materials prepared in Examples 1-3 at a current density of 5 A / g is shown in the figure. Figure 11 .

[0164] from Figure 11 As can be seen, the three-dimensional hierarchical porous MoS2 materials prepared in Examples 1-3 still exhibit extremely high cycling stability after 2500 charge-discharge cycles at a current density of 5 A / g. The specific capacity of the three-dimensional hierarchical porous MoS2 material 1 prepared in Example 1 after cycling is 301.8 mAh / g, with a capacity retention of approximately 100%; the specific capacity of the three-dimensional hierarchical porous MoS2 material 2 prepared in Example 2 after cycling is 352.7 mAh / g, with a capacity retention of approximately 100%; and the specific capacity of the three-dimensional hierarchical porous MoS2 material 3 prepared in Example 3 after cycling is 282.5 mAh / g, with a capacity retention of approximately 84.8%.

[0165] (6) The cycling performance of the three-dimensional hierarchical porous MoS2 materials prepared in Examples 1-3 at a current density of 20 A / g is shown in the figure. Figure 12 .

[0166] from Figure 12 As can be seen, the three-dimensional hierarchical porous MoS2 materials prepared in Examples 1-3 maintained high specific capacity and structural stability after 2500 cycles at a higher current density of 20 A / g. The specific capacity of the three-dimensional hierarchical porous MoS2 material 1 prepared in Example 1 after cycling was 297.2 mAh / g, with a capacity retention of approximately 100%; the specific capacity of the three-dimensional hierarchical porous MoS2 material 2 prepared in Example 2 after cycling was 298.9 mA h / g, with a capacity retention of 98.6%; and the specific capacity of the three-dimensional hierarchical porous MoS2 material 3 prepared in Example 3 after cycling was 291.2 mAh / g, with a capacity retention of 93.6%.

[0167] (7) Scanning electron microscope images of the three-dimensional hierarchical porous MoS2 material 2 prepared in Example 2 before and after charge-discharge cycles are shown below. Figure 13 , Figure 13 In the figures, (a) is the original electrode before cycling, (b) is the electrode after 1 cycle at 0.1 A / g, (c) is the electrode after 500 cycles at 5 A / g, and (d) is the electrode after 1000 cycles at 5 A / g.

[0168] from Figure 13 As can be seen in Figure (a), the surface of the original electrode sheet obtained using the three-dimensional hierarchical porous MoS2 material 2 prepared in Example 2 is composed of uniformly distributed particles, with a clear pore structure; from Figure 13 As can be seen in Figures (b), (c), and (d), under different current densities and number of cycles, the overall particle morphology and pore structure of the electrode material are basically consistent with the original electrode material, and no obvious agglomeration or structural collapse is observed, indicating that the material can still maintain good structural stability during long-term cycling.

[0169] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. The application of a three-dimensional hierarchical porous MoS2 material in fast-charging sodium-ion batteries, characterized in that, The preparation method of the three-dimensional hierarchical porous MoS2 material includes the following steps: (1) Add a mixed solution of tetraethyl orthosilicate and cyclohexane to a micelle solution containing an organic quaternary ammonium cation surfactant and triethanolamine, and after the reaction, dendritic mesoporous SiO2 nanospheres are obtained. (2) A bimicelle mixture was prepared by combining a molybdenum source, a surfactant containing organic quaternary ammonium cations, and a block copolymer. Then, the dendritic mesoporous SiO2 nanospheres were added, and the mixture was reacted to obtain MoO2. x / SiO2 composite precursor; (3) Under an inert atmosphere, the MoO was treated with thiourea. x MoS2 / SiO2 composite material was obtained by confined sulfurization of the / SiO2 composite precursor. (4) The MoS2 / SiO2 composite material is dispersed in an alkaline solution and etched to obtain the three-dimensional hierarchical porous MoS2 material; The pore structure of the three-dimensional hierarchical porous MoS2 material includes mesopores and macropores. The mesopores are mainly distributed in the small size range of 2 to 10 nm, and the most probable pore diameter is 2.5 to 4.5 nm. The three-dimensional hierarchical porous MoS2 material has a few-layer structure with 1 to 6 layers and an interlayer spacing of 0.68 to 0.71 nm. The specific surface area of ​​the three-dimensional hierarchical porous MoS2 material is 40-45 m². 2 / g, pore volume is 0.15~0.25cm³ 3 / g.

2. The application according to claim 1, characterized in that, The surfactant containing organic quaternary ammonium cations includes one or more of hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, dodecyltrimethylammonium bromide, and octadecyltrimethylammonium bromide.

3. The application according to claim 1, characterized in that, In step (1), the ratio of the surfactant containing the organic quaternary ammonium cation, triethanolamine, tetraethyl orthosilicate and cyclohexane is 1.5-6 g: 0.4-1.4 mL: 3-6 mL: 15-25 mL; And / or, triethanolamine is an aqueous solution with a concentration of 0.35 g / mL; And / or, the reaction time is 12 to 20 hours.

4. The application according to claim 1, characterized in that, In step (2), the molybdenum source includes ammonium molybdate and / or sodium molybdate; And / or, the block copolymer includes Pluronic F127; And / or, the mass ratio of the surfactant containing the organic quaternary ammonium cation, the block copolymer, and the dendritic mesoporous SiO2 nanospheres is (0.2–1):(0.2–1):(0.3–0.5); And / or, the mass ratio of the dendritic mesoporous SiO2 nanospheres to the molybdenum source is 1:(8-25).

5. The application according to claim 1, characterized in that, In step (3), the MoO x The mass ratio of the SiO2 composite precursor to thiourea is 1:(1-3).

6. The application according to claim 1, characterized in that, In step (3), the heating rate of the confined vulcanization is 5-10℃ / min, the temperature is 500-800℃, and the time is 2-5h; And / or, the inert atmosphere is a nitrogen atmosphere and / or an argon atmosphere, and the flow rate is 20-60 mL / min.

7. The application according to claim 1, characterized in that, In step (4), the alkaline solution includes an aqueous solution of sodium hydroxide; And / or, the concentration of the sodium hydroxide aqueous solution is 2–4 mol / L; And / or, the etching process takes 6 to 12 hours.

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