Preparation method of high-initial-efficiency three-dimensional SnS2 graphene lithium ion battery negative electrode material with adjustable cavity

Abstract

The application is a preparation method of high initial efficiency three-dimensional SnS2 graphene lithium ion battery negative material with adjustable cavity. The application takes PS spheres as templates, obtains a mixed dispersion liquid of metal salt and graphene oxide mixed uniformly with the PS spheres through electrostatic combination, and finally obtains a three-dimensional graphene structure with internal anchoring SnS2 cavity through one-step calcination. The lithium ion battery assembled by the composite material has a first discharge capacity of 1633mA h g ‑1 at 0.2A g ‑1 , a reversible specific capacity of 1215mA h g ‑1 after 100 cycles, a first coulomb efficiency of 88%, and excellent cycle stability and high reversible specific capacity at low current density.

Description

Technical Field

[0001] This invention belongs to the field of energy storage materials, specifically developing a method for preparing a high-efficiency three-dimensional SnS2 graphene lithium-ion battery anode material with an adjustable cavity. The invention first prepares PS@SnO2@GO using a template-guided self-assembly strategy, then adds thiourea and undergoes a calcination reaction to finally obtain a high-efficiency three-dimensional SnS2 graphene (3D-SnS2@rGO) composite material with an adjustable cavity. This material exhibits excellent cycle stability and high reversible specific capacity at different current densities. This novel preparation method of tin disulfide graphene anode material with an adjustable cavity lays the foundation for the application of high-performance transition metal sulfide-based anode materials. Background Technology

[0002] Driven by the ever-growing market demand for new energy vehicles, electronic products, and aerospace power supplies, the development of advanced energy storage systems with high energy density, long lifespan, and good cycle stability is particularly important. Graphite, as a negative electrode material for commercial lithium-ion batteries, possesses advantages such as chemical stability, a low charge / discharge potential plateau, and minimal volume expansion. However, graphite negative electrodes have a relatively low theoretical specific capacity (372 mAh g⁻¹). -1 However, current methods cannot meet the demands for more powerful electronic devices. In this regard, SnS2 and MoS2, as typical tin-based and molybdenum-based compound materials, possess lower lithium intercalation voltages and higher theoretical capacities, making them promising anode materials for lithium-ion batteries (LIBs). Furthermore, compared to oxides, metal sulfides exhibit higher electrochemical reactivity and reversibility due to their weaker metal-sulfur bonds. However, their low conductivity and slow reaction kinetics hinder their full capacity utilization, resulting in poor rate performance. Additionally, the high volume expansion rate of metal sulfides leads to electrode pulverization during lithium intercalation / deintercalation. Composite materials using PS as a substrate with graphene are an effective way to solve the problems of metal sulfide anodes. The addition of PS spheres and graphene can significantly improve the material's conductivity and ion transfer efficiency, while also increasing its structural stability.

[0003] In traditional synthesis methods, SnS2 is mainly grown in situ on the surface of two-dimensional graphene nanosheets. For example, patent CN106129378A proposes to grow SnS2 in situ on the graphene surface through a hydrothermal process. However, this method can easily cause SnS2 nanosheets to agglomerate. At the same time, SnS2 is directly exposed to the electrolyte environment, resulting in disordered growth of the SEI film and causing the shuttle effect. Summary of the Invention

[0004] This invention addresses the problems of disordered growth of the SEI film on the tin disulfide surface and the stacking of graphene sheets in traditional preparation methods, which lead to difficulties in maintaining a stable structure during cycling. It provides a method for preparing a high-efficiency three-dimensional SnS2 graphene lithium-ion battery anode material with adjustable cavities. This invention uses PS spheres as templates, and obtains a uniformly mixed dispersion of metal salt and graphene oxide with the PS spheres through electrostatic bonding. After a one-step calcination, a three-dimensional graphene structure with internally anchored SnS2 cavities is finally obtained. This invention eliminates the need for a purification process, and the lithium-ion battery assembled from the composite material achieves a high efficiency of 0.2 A g. -1 The initial discharge capacity reached 1633 mA hg -1 The reversible specific capacity after 100 cycles reaches 1215 mA hg. -1 It achieves an initial coulombic efficiency of up to 88%. It exhibits excellent cycle stability and high reversible specific capacity at low current densities.

[0005] The technical solution of this invention is:

[0006] A method for preparing a high-efficiency three-dimensional SnS2 graphene lithium-ion battery anode material with an adjustable cavity, the method comprising the following steps:

[0007] (1) Dissolve an inorganic metal salt in deionized water, which is called solution A. Then, add NaOH to solution A with stirring. When the solution changes from clear to turbid until it becomes clear again, you get solution B.

[0008] For every 10–100 mL of deionized water, add 0.1–2.0 g of inorganic metal salt and 500–800 mg of NaOH.

[0009] The inorganic metal salt is tin tetrachloride pentahydrate (SnCl4·5H2O) or ammonium molybdate ((NH4)2MoO4);

[0010] (2) Add solution B dropwise to the PS ball dispersion to form a metal salt@PS dispersion solution;

[0011] The mass concentration of the PS spherical solution was 0.1–5 mg / mL. -1 The volume ratio of PS ball dispersion to solution B is 4–12:1.

[0012] When the metal salt in step (1) is tin tetrachloride pentahydrate, the surfactant polyvinylpyrrolidone (PVP) should also be added to the PS spherical dispersion and mixed for 1 to 5 hours. The mass ratio of PS spherical solution to PVP is 1:0.1 to 2.

[0013] The particle size of PS spheres is 80–570 nm;

[0014] (3) Add hydrochloric acid to the metal salt@PS dispersion solution to make the pH value neutral, and obtain the metal oxide@PS dispersion;

[0015] The concentration of hydrochloric acid is 0.1–2 mol / L. -1 ;

[0016] (4) Preparation of metal oxide @PS@rGO compounds:

[0017] The GO dispersion was added to the metal oxide@PS dispersion and stirred for 4–8 hours. Then, sodium ascorbate was added, and stirring was continued at 80–120 °C for 0.1–2 hours. The mixture was then centrifuged, washed, and freeze-dried to obtain the metal oxide@PS@rGO compound.

[0018] The mass concentration of the GO dispersion was 0.1–2 mg / mL. -1 Add 300-450 mg of sodium ascorbate to every 200-250 ml of metal oxide@PS dispersion. The volume ratio of GO dispersion to metal oxide@PS dispersion is 1:10-20.

[0019] (5) High-temperature vulcanization:

[0020] Thiourea and metal oxide @PS@rGO were placed sequentially in a glass container. A ceramic boat containing thiourea was placed upstream of the container, and the solid product metal oxide @PS@rGO was placed downstream of the container. The glass container was then placed in a tube furnace and heat-treated at 300–500°C for 1–5 hours under an inert atmosphere to obtain a high-efficiency three-dimensional SnS2 graphene lithium-ion battery anode material with an adjustable cavity.

[0021] For every 0.20–1.00 g of inorganic metal, 2–4 g of thiourea is added to the metal oxide @PS@rGO compound;

[0022] The graphene oxide in step (4) is graphene oxide prepared by the improved Hummers method.

[0023] The inert gas mentioned is argon;

[0024] The "cavity size" is 105–596 nm.

[0025] The method described the application of a high-efficiency three-dimensional SnS2 graphene lithium-ion battery anode material with adjustable cavity, which is used as an anode sheet for lithium-ion batteries.

[0026] The process includes the following steps: mixing the electrode material obtained in step (5) with conductive carbon and binder at a mass ratio of 8:1:1 to obtain a mixed material; adding deionized water and stirring at room temperature for 6–24 hours; after stirring, uniformly coating the resulting suspension onto copper foil with a coating amount of 0.5–2 mg / cm² per unit area. -2 The negative electrode sheet for lithium-ion batteries is obtained by vacuum drying at 80–120°C for 10–20 hours.

[0027] Add 50–250 mg of the mixed material to every 600–1000 μL of deionized water;

[0028] The binder is sodium carboxymethyl cellulose, and the conductive carbon is Super P.

[0029] The positive electrode of the lithium-ion battery is a lithium metal sheet, the separator is a glass fiber membrane, and the electrolyte is 1.0 mol / L. - 1 A solution of LiPF6 in a mixture of dimethyl carbonate (DMC), methyl ethyl carbonate (EMC), and ethylene carbonate (EC) in a volume ratio of 1:1:1.

[0030] The essential features of this invention are:

[0031] In previous invention patents, the preparation of metal sulfide and graphene composite materials usually involved the removal of impurities, and the synthesis process was relatively complicated. Furthermore, the traditional one-pot hydrothermal method combined with high-temperature calcination made it difficult to effectively control the nanostructure of the composite material. This made it difficult to fully utilize the advantages of the metal sulfide anode material itself, and the volume expansion problem during lithium ion insertion / extraction also needed to be solved.

[0032] This invention uses easily decomposable inorganic metal salts and thiourea as metal and sulfur sources, respectively, and tunably sized PS spheres and graphene nanosheets as conductive substrates. Through the electrostatic bonding between metal ions and graphene oxide (GO) nanosheets, inorganic metal salts uniformly attached to the PS sphere surface are adsorbed onto the GO surface as "seeds." After centrifugation, washing, and freeze-drying, the metal salts are anchored onto the GO nanosheets. Finally, high-temperature vulcanization yields a three-dimensional SnS2 graphene heterostructure composite material with tunable cavities. The inventors discovered that composite materials designed and synthesized through the self-assembly of various conductive substrates, using PS spheres as basic units, can provide a large number of electrochemical reaction active sites. Simultaneously, the excellent stress-bearing capacity of the PS sphere cavities effectively alleviates the volume expansion problem during charging and discharging, further increasing the structural stability of the material. Moreover, this directional and compact arrangement provides multiple high-speed transport channels for lithium-ion conduction. In addition, the nitrogen and sulfur elements produced after the decomposition of thiourea can be incorporated into the carbon skeleton of the metal salt lattice and graphene sheets, which can greatly improve conductivity, accelerate charge transport, reduce the lithium ion migration barrier, and further improve the electrochemical performance of the material.

[0033] The beneficial effects of this invention are as follows:

[0034] (1) This invention introduces PS spheres as templates to transform two-dimensional graphene into a three-dimensional network structure. The metal salts uniformly attached to the surface of the PS spheres are adsorbed onto GO nanosheets through electrostatic interaction, so that SnS2 grows in the cavity of the PS spheres, resulting in a three-dimensional graphene hybrid material that is different from traditional two-dimensional materials.

[0035] (2) The present invention utilizes electrostatic adsorption to uniformly attach metal salt ions to positively charged PS spheres on the surface, and adjusts the pH value to convert the metal salt ions into hydroxides.

[0036] (3) PS spheres coated with tin hydroxide are uniformly attached to the surface of negatively charged graphene oxide sheets. The operation is simple and the experimental conditions are mild.

[0037] (4) In-situ growth of metal sulfide nanoparticles in three-dimensional network graphene was achieved through high-temperature sulfidation and calcination. The 3D-SnS2@rGO-310 anode material prepared under optimal conditions in this experiment was successfully grown at 0.2 A g. -1 The reversible specific capacity reaches 1215 mA hg after 100 cycles. -1 Meanwhile, in 1A g -1 It can still maintain 910 mA hg after 1000 charge-discharge cycles at current density. -1 Reversible specific capacity;

[0038] (5) The 3D-MoS2@rGO-310 anode material prepared under optimal conditions in this experiment was at 0.2 A g. -1 The reversible specific capacity reaches 940 mA hg after 100 cycles. -1 ;

[0039] (6) The present invention can also replace different metal salt precursors to realize the construction of three-dimensional graphene hybrid materials with adjustable cavities. Attached Figure Description

[0040] Figure 1 This is a scanning electron microscope image of the 3D-SnS2@rGO-310 composite material in Example 1;

[0041] Figure 2 The X-ray diffraction pattern of the 3D-SnS2@rGO-310 composite material in Example 1;

[0042] Figure 3 The 3D-SnS2@rGO-310 composite material in Example 1 was used at 0.2A g. -1 Cyclic performance at current density;

[0043] Figure 4 The 3D-SnS2@rGO-310 composite material in Example 1 at 1A g -1 Cyclic performance at current density;

[0044] Figure 5 This is a rate performance diagram of the 3D-SnS2@rGO-310 composite material in Example 1;

[0045] Figure 6 The 3D-SnS2@rGO-570 composite material in Example 2 was used at 0.2A g. -1 Cyclic performance at current density;

[0046] Figure 7 The 3D-SnS2@rGO-80 composite material in Example 3 was used at 0.2A g. -1 Cyclic performance at current density;

[0047] Figure 8 The SnS2@rGO composite material in Example 4 at 0.2A g -1 Cyclic performance at current density;

[0048] Figure 9 This is a scanning electron microscope image of the 3D-MoS2@rGO-310 composite material in Example 5;

[0049] Figure 10The XRD test curve of the 3D-MoS2@rGO-310 composite material in Example 5;

[0050] Figure 11 The 3D-MoS2@rGO-310 composite material in Example 5 was measured at 0.2A g. -1 Cyclic performance at current density; Detailed Implementation

[0051] In this invention, PS spheres are introduced into the composite system as templates to construct a three-dimensional graphene network with adjustable cavities, allowing SnS2 to grow in the spherical cavities. The three-dimensional graphene network avoids the stacking phenomenon caused by van der Waals forces between the original two-dimensional sheets. At the same time, under the protection of the spherical cavities, SnS2 avoids direct contact with the electrolyte, promoting the controllable growth of the SEI film.

[0052] In the preparation process, an inorganic metal salt is first prepared into an aqueous solution, and NaOH solution is added to obtain a homogeneous inorganic metal salt solution. This solution is then mixed with a homogeneous PVP-based PS spherical solution to form a metal salt@PS dispersion. Next, this dispersion is mixed evenly with a graphene oxide dispersion, and sodium ascorbate is added and stirred until homogeneous. The dispersion is then centrifuged, washed, and freeze-dried to form a metal hydroxide@PS@rGO compound. After high-temperature sulfidation, a composite material with a three-dimensional SnS2 graphene heterostructure and adjustable cavities is finally obtained. This material exhibits high reversible specific capacity and excellent rate performance. This novel preparation method of the metal sulfide-graphene heterostructure anode material lays the foundation for the application of high-performance metal sulfide anode materials in the energy storage field.

[0053] Example 1

[0054] Add 0.701 g of tin tetrachloride pentahydrate to 20 mL of deionized water and stir to obtain Sn. 4+ A solution, denoted as solution A, is gradually added to it with solid NaOH. The solution changes from clear to cloudy until it becomes clear again (approximately 650 mg of NaOH is added). Sn 4+ It is converted into SnO3 2- Let this be solution B. Then, a pre-prepared polystyrene (PS) spherical solution (200 mL, 1 mg / mL) with a diameter of 310 nm was added. -1 (Document No.: Adv. Funct. Mater. 2017, 27, 1702807) Mixed with 40 mg PVP for 2 hours, while simultaneously adding all of the prepared solution B dropwise. Under electrostatic force, the two combine to form SnO3. 2- @PS dispersion. Then add 0.5 mol / L to the solution. -1Use HCl to neutralize the pH, and stir the solution for 2 hours until it is thoroughly mixed, thereby removing SnO3. 2- @PS was converted into SnO2@PS dispersion. Graphene oxide (GO-) was prepared based on the modified Hummers method (Journal of Alloys and Compounds 862(2021)158472) dispersion (15 mL, 2 mg / mL). -1 Add 0.396 g of sodium ascorbate to the SnO2@PS dispersion prepared above and stir for 6 hours. Then, add 0.396 g of sodium ascorbate and continue stirring at 90 °C for 2 hours. Centrifuge, wash and freeze-dry the dispersion to obtain Sn(OH)4@PS@rGO solid product; place 3 g of thiourea and all the prepared Sn(OH)4@PS@rGO solid product in a specific glass container, place the porcelain boat containing thiourea at the upstream end of the container, and place all the Sn(OH)4@PS@rGO solid product at the downstream end of the container. Then place the glass container in a tube furnace and heat at an argon atmosphere (from upstream to downstream at a speed of 120 mL / min). -1 Under the protection of a flow rate purging, the material was heat-treated at 500℃ for 3h with a heating rate of 10℃ / min. After calcination, the cavity size was 342nm, resulting in a three-dimensional SnS2@graphene composite material with adjustable cavity (labeled as 3D-SnS2@rGO-310).

[0055] The obtained 3D-SnS2@rGO-310 composite material was uniformly mixed with conductive carbon (Super P) and binder (sodium carboxymethyl cellulose) at a mass ratio of 8:1:1 (total amount of 125 mg) to obtain SnS2@graphene composite material. 800 μL of deionized water was added, and the mixture was stirred at room temperature for 12 h. After stirring, the obtained SnS2@graphene composite material suspension was uniformly coated onto copper foil (approximately 1 mg coating per square centimeter of copper foil) and vacuum dried at 100 °C for 12 h. The resulting electrode sheet was cut into 12 mm diameter circular pieces using a manual slicer to obtain the negative electrode sheet. In this embodiment, the battery adopts a standard half-cell configuration, with a CR2025 stainless steel coin cell casing, a lithium sheet as the counter electrode, Celgard 2500 as the separator, and a 1 M LiPF6 mixed solution of ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC) (volume ratio 1:1:1). The voltage range for this test is 0.01–3V, and the test current is 0.2A. -1 The test was conducted using the LAND CT2001A battery testing system.

[0056] Figure 1This is a scanning electron microscope (SEM) image of the 3D-SnS2@rGO-310 composite material from Example 1. The image shows that PS spheres are uniformly attached to graphene, and tin disulfide nanosheets grow within the spherical cavities without significant agglomeration. Throughout the process, the PS spheres, externally coated with tin oxide, are embedded into the graphene during stirring. During the subsequent calcination process, the PS spheres are removed, and the tin oxide is converted to tin disulfide. The final cavity size includes the thickness of the SnS2 spheres; in this example, the PS sphere size is 310 nm, and the cavity size is 342 nm.

[0057] Figure 2 The image shows the XRD test curve of the 3D-SnS2@rGO-310 composite material in Example 1. It shows a tin disulfide crystal structure. No obvious graphene characteristic diffraction peaks were observed in the figure. This is because the diffraction peaks of tin disulfide are strong, thus obscuring the peaks of graphene.

[0058] Figure 3 The 3D-SnS2@rGO-310 composite material in Example 1 was used at 0.2A g. -1 Cyclic performance at current density. The discharge and charge specific capacities of this composite material in the first cycle are 1633 and 1439 mA hg, respectively. -1 The initial coulomb efficiency reached 88%, and the reversible specific capacity after 100 cycles reached 1215 mA hg. -1 The Coulomb efficiency is close to 100%.

[0059] Figure 4 For 3D-SnS2@rGO-310 composite material in 1A g -1 Cyclic performance at current density. The reversible specific capacity of this composite material reaches 910 mA hg after 1000 cycles. -1 The Coulomb efficiency is close to 100%.

[0060] Figure 5 This is a rate performance diagram of the 3D-SnS2@rGO-310 composite material. The composite material at 2A g... -1 and 5Ag -1 The reversible specific capacity at the current density reached 1132 mAh g. -1 and 977mA hg -1 This indicates its excellent rate performance.

[0061] Example 2

[0062] The steps are the same as in Example 1, except that the size of the PS sphere (570nm) and the cavity size (596nm) are changed, while other conditions remain the same. The resulting composite material is denoted as 3D-SnS2@rGO-570.

[0063] Figure 6 For 3D-SnS2@rGO-570 composite material at 0.2A g -1 Cyclic performance at current density. The discharge and charge specific capacities of this composite material in the first cycle are 1257 and 1024 mA hg, respectively. -1 The reversible specific capacity reaches 945 mA hg after 100 cycles. -1 .

[0064] Example 3

[0065] The steps are the same as in Example 1, except that the size of the PS sphere (80nm) and the cavity size are changed to 105nm, while other conditions remain unchanged. The resulting composite material is denoted as 3D-SnS2@rGO-80.

[0066] Figure 7 For 3D-SnS2@rGO-80 composite materials at 0.2A g -1 Cycling performance at current density. The discharge and charge specific capacities of this composite material in the first cycle are 1294 and 1030 mA hg, respectively. -1 The reversible specific capacity reaches 898 mA hg after 100 cycles. -1 .

[0067] Example 4

[0068] The steps are the same as in Example 1, except that PS sphere solution is not added and other conditions remain unchanged. The final composite material is denoted as SnS2@rGO.

[0069] Figure 8 For SnS2@rGO composite materials at 0.2A g -1 Cycling performance at current density. The discharge and charge specific capacities of this composite material in the first cycle are 1578 and 1122 mA hg, respectively. -1 The reversible specific capacity reaches 745 mA hg after 100 cycles. -1 This demonstrates that, compared to two-dimensional graphene structures, introducing PS spheres as templates to construct a three-dimensional graphene network with cavities enables in-situ growth of SnS2 nanoparticles within the cavities. The three-dimensional conductive network provides more channels for lithium-ion electron transport, while the cavities effectively alleviate the volume expansion of SnS2 during cycling. Based on these structural advantages, the anode material exhibits extremely high first-efficiency and superior reversible specific capacity.

[0070] Example 5

[0071] The steps are the same as in Example 1, except that the tin tetrachloride pentahydrate added to dispersion A is replaced with ammonium molybdate, with an added mass of 0.392g. When mixing with the PS spherical solution, the surfactant PVP is not required. Other conditions remain unchanged. The final composite material is denoted as 3D-MoS2@rGO-310.

[0072] Figure 9 This is a scanning electron microscope image of the 3D-MoS2@rGO-310 composite material, in which MoS2 nanoparticles grown on the graphene surface can be observed.

[0073] Figure 10 The XRD test curves for the 3D-MoS2@rGO-310 composite material are shown.

[0074] Figure 11 The graph shows the cycling performance of the 3D-MoS2@rGO-310 composite material. The discharge and charge specific capacities of this composite material in the first cycle are 1151 and 920 mA hg, respectively. -1 The reversible specific capacity reaches 940 mA hg after 100 cycles. -1 The Coulomb efficiency is close to 100%.

[0075] Matters not covered in this invention are common knowledge.

Claims

1. A method for preparing high initial efficiency three-dimensional SnS2 graphene lithium-ion battery anode material with adjustable cavities, characterized in that, The method comprises the following steps: (1) Dissolve the inorganic metal salt in deionized water, which is called solution A, then add NaOH to solution A under stirring, and obtain solution B when the solution changes from clear to turbid until the solution becomes clear again; wherein 0.1-2.0 g of inorganic metal salt and 500-800 mg of NaOH are added per 10-100 mL of deionized water; the inorganic metal salt is tin tetrachloride pentahydrate (SnCl4·5H2O); (2) Add solution B dropwise to the PS ball dispersion solution to form a metal salt@PS dispersion solution; The mass concentration of the PS spherical solution is 0.1-5 mg / mL -1 ; the volume ratio of the PS spherical dispersion and solution B is 4-12:1; When the metal salt in step (1) is tin tetrachloride pentahydrate, a surfactant polyvinylpyrrolidone (PVP) is also added to the PS ball dispersion solution, and the mixture is mixed for 1-5 hours, and the mass ratio of the PS spherical solution to PVP is 1:0.1-2; (3) Add hydrochloric acid to the metal salt@PS dispersion solution to make the pH value neutral, and obtain a metal oxide@PS dispersion solution; wherein the concentration of hydrochloric acid is 0.1-2 mol L -1 ; (4) Preparation of a metal oxide@PS@rGO compound: Add the GO dispersion solution to the metal oxide@PS dispersion solution and stir for 4-8 hours, then add sodium ascorbate, and continue to stir at 80-120°C for 0.1-2 hours; then centrifuge, wash and freeze-dry to obtain a metal oxide@PS@rGO compound; The mass concentration of the GO dispersion liquid is 0.1-2 mg / mL -1 The volume ratio of the GO dispersion liquid to the metal oxide@PS dispersion liquid is 1:10-20. (5) High-temperature vulcanization: Place thiourea and the metal oxide@PS@rGO in a glass container in sequence, place the porcelain boat containing thiourea in the upstream of the container, and place the solid product metal oxide@PS@rGO in the downstream of the container, then place the glass container in a tube furnace, and heat treat at 300-500°C for 1-5 hours under the protection of an inert atmosphere to obtain a high-initial-efficiency three-dimensional SnS2 graphene lithium ion battery negative electrode material with adjustable cavities; wherein 2-4 g of thiourea is added per 0.20-1.00 g of inorganic metal to obtain a metal oxide@PS@rGO compound.

2. The method for preparing high initial efficiency three-dimensional SnS2 graphene lithium-ion battery anode material with adjustable cavity according to claim 1, characterized in that, The graphene oxide in step (4) is graphene oxide prepared by an improved Hummers method.

3. The method for preparing high initial efficiency three-dimensional SnS2 graphene lithium-ion battery anode material with adjustable cavity according to claim 1, characterized in that, The inert atmosphere is argon.

4. The method for preparing high initial efficiency three-dimensional SnS2 graphene lithium-ion battery anode material with adjustable cavity according to claim 1, characterized in that, The particle size of the PS balls is 80-570 nm, and the cavity size is 105-596 nm.

5. Application of a high-initial-efficiency three-dimensional SnS2 graphene lithium ion battery negative electrode material with adjustable cavities prepared by the method of claim 1, characterized by being used as a negative electrode sheet of a lithium ion battery.

6. The use as claimed in claim 5, characterised in that comprises the following steps: The electrode material obtained in (5) is mixed with conductive carbon and a binder at a mass ratio of 8:1:1 to obtain a mixed material, deionized water is added, and stirring is performed at room temperature for 6-24 h; after the stirring is completed, the obtained suspension is uniformly coated on a copper foil, and the coating amount per unit area is 0.5-2 mg cm -2 , and vacuum drying is performed at 80-120 °C for 10-20 h to obtain a negative electrode sheet of a lithium ion battery. 50-250 mg of the mixed material is added per 600-1000 µL of deionized water; the binder is sodium carboxymethyl cellulose, and the conductive carbon is Super P; The positive electrode of the lithium ion battery is a metal lithium sheet, the diaphragm is a glass fiber membrane, and the electrolyte is 1.0 mol / L -1 LiPF6 solution in a mixture of dimethyl carbonate (DMC), methyl ethyl carbonate (EMC) and ethylene carbonate (EC) in a volume ratio of 1:1:1.

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