A Sb2S3@Sb6O 13 @rGO composite material and its preparation method and application

Abstract

The present invention discloses a Sb2S3@Sb6O 13 @rGO composite material and its preparation method and application, the Sb2S3@Sb6O 13 The @rGO composite material is prepared by dissolving antimony salt, L-tartaric acid and a sulfiding agent in deionized water, stirring and mixing them, then adding polyvinyl pyrrolidone to the mixture, stirring and reacting, transferring it to a stainless steel reactor, reacting it at 100-200°C for 15-28 hours, filtering it and freeze-drying it to prepare spherical antimony sulfide, then placing the spherical antimony sulfide in a tube furnace under a gas atmosphere and reacting it for 1-5 hours, and then cooling it with the furnace to obtain an intermediate product Sb2S3 / Sb composite material. The Sb2S3 / Sb composite material obtained in the previous step is dissolved in deionized water, subjected to ultrasonication, mixed with a graphene oxide solution, and transferred to a stainless steel reactor for a second hydrothermal reaction. The sample collected after filtering and freeze-drying is Sb2S3@Sb6O 13 @rGO composite material.

Description

Technical Field

[0001] The present invention relates to the technical field of preparation of negative electrode materials for lithium ion batteries, and in particular to a Sb2S3@Sb6O 13 @rGO composite material, preparation method and application thereof. Background Art

[0002] Lithium-ion batteries have the advantages of high voltage, high energy density, good safety performance, and good safety performance. At present, the research on lithium-ion batteries has entered a new stage, and the search for new electrode materials has become the current main task. Traditional lithium-ion battery negative electrode materials are carbon materials, but currently carbon materials have defects such as large energy loss and poor rate performance; carbon materials easily form passivation films in organic electrolytes, causing irreversible loss of capacity; and the electrolysis potential of carbon electrodes is close to that of metal electrodes. During the charge and discharge process, metal is easily precipitated on the surface of the carbon electrode, forming dendrites and causing short circuits. This can no longer fully meet the current market demand. Therefore, the search for new lithium-ion battery negative electrode materials that can embed lithium at a potential slightly higher than the carbon negative electrode potential and have reliable safety performance has become a research direction.

[0003] Metal sulfides have a high theoretical specific capacity, and compared with metal oxides, since the oxygen element is replaced by the sulfur element, the volume expansion rate of metal sulfides during the charge and discharge process is relatively small compared to metal oxides. However, the excessively large volume expansion coefficient is still the main reason restricting the application of metal sulfides in battery negative electrode materials. Antimony sulfide has a very potential theoretical specific capacity, abundant reserves, simple preparation, and low cost. However, when it is used as a negative electrode material, the alloying reaction causes volume expansion, resulting in the crushing of the active material, resulting in low first-cycle coulombic efficiency and poor electrochemical performance, which limits its use in lithium batteries. Summary of the Invention

[0004] The present invention provides a Sb2S3@Sb6O 13 Preparation method of Sb2S3@Sb6O@rGO composite material 13 The preparation method of @rGO composite material can effectively alleviate the volume expansion effect produced during the charge and discharge process, thereby improving the electrochemical performance. In addition, in terms of capacity, in addition to antimony sulfide, Sb6O 13 It can also provide capacity, which is one of the factors for its excellent electrochemical performance. The preparation method of the present invention is simple, low in cost, and high in output, and is suitable for industrial mass production.

[0005] A Sb2S3@Sb6O 13 The preparation method of the @rGO composite material comprises the following steps:

[0006] S1: Dissolve soluble antimony salt, L-tartaric acid and sulfiding agent in a beaker filled with deionized water to obtain a mixed solution A;

[0007] S2: adding polyvinyl pyrrolidone to solution A to obtain a mixed solution C;

[0008] S3: Transfer solution C to a stainless steel reactor for hydrothermal reaction, filter and dry to obtain solid D;

[0009] S4: placing solid D in a tube furnace, sintering under a gas atmosphere and cooling the furnace to obtain an intermediate product E;

[0010] S5: The intermediate product E was dissolved in deionized water, sonicated, mixed with the graphene oxide solution, and then transferred to a stainless steel reactor for a second hydrothermal reaction;

[0011] S6: After the hydrothermal reaction, the solid F is obtained by cooling in the furnace, filtering and drying;

[0012] S7: After freeze-drying solid F, Sb2S3@Sb6O is obtained. 13 @rGO composite material.

[0013] Preferably, the solid D is spherical antimony sulfide.

[0014] Preferably, the antimony salt is one or more of antimony nitrate, antimony bromide, antimony trichloride, antimony sulfide, antimony pentachloride, antimony sulfate, and antimony hydroxide.

[0015] Preferably, the polyvinyl pyrrolidone is used to modify the shape of the spherical antimony sulfide.

[0016] Preferably, the vulcanizing agent is one or more of sodium sulfide, thioacetamide, and L-cysteine.

[0017] Preferably, the gas atmosphere of the spherical antimony sulfide in the tube furnace is one or more of N2 / H2, Ar2 / H2, N2, and Ar2.

[0018] Preferably, the drying method is freeze drying, the drying time is 10-48 hours, and the hydrothermal reaction parameters are 100-200° C. for 15-28 hours.

[0019] Preferably, the sintering time in the tube furnace is 1 to 5 hours.

[0020] And provide a Sb2S3@Sb6O 13 @rGO composite material is prepared by the preparation method.

[0021] And provide a Sb2S3@Sb6O 13Application of Sb2S3@Sb6O@rGO composite materials 13 Application of @rGO composite materials in the field of lithium-ion battery anode materials.

[0022] In summary, the present invention has the following beneficial effects compared to the prior art:

[0023] The Sb2S3@Sb6O of the present invention 13 The microstructure of the @rGO composite material is spherical and wrapped with graphene. This structure can increase the specific surface area, allow the insertion and extraction of lithium ions, reduce the coating of graphite tin oxide, further alleviate the volume expansion, and improve both the rate performance and cyclability.

[0024] In this invention, Sb2S3 and Sb6O are combined for the first time. 13 Combined with reduced graphene oxide, it not only effectively prints the volume expansion during the charge and discharge process, but also due to the Sb6O 13 The addition of reduced graphene oxide not only increases the capacity but also reduces the capacity decay rate during charge and discharge, further improving the stability of the Sb2S3 material. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Sb2S3@Sb6O in the present invention 13 SEM image of @rGO composite material. DETAILED DESCRIPTION

[0026] The present invention will be further described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

[0027] Example 1

[0028] Step 1: Weigh 1 mmol of SbCl3, L-cysteine, and L-tartaric acid respectively and dissolve them in a beaker to obtain solution A;

[0029] Step 2: Weigh 6 g of polyethylene polyvinyl pyrrolidone and add it to solution A. After halving, transfer it to a stainless steel reactor and place it in a heating box at 120°C for 12 hours. After cooling in the furnace, collect the antimony sulfide sample.

[0030] Step 3, weighing 1 mmol of the antimony sulfide prepared in step 2, placing it in a vacuum tube furnace, sintering it at 400°C for 3 hours in a mixed atmosphere of hydrogen and argon, and then cooling the furnace to obtain an intermediate product, Sb2S3 / Sb composite material;

[0031] Step 4: Continue to weigh the Sb2S3 / Sb composite material prepared in step 3, dissolve it in deionized water, and then perform ultrasonic treatment. Then, mix it with the graphene oxide solution, stir it evenly, and transfer it to a stainless steel reactor for a second hydrothermal reaction. Set the hydrothermal temperature to 120°C for 12 hours. After cooling in the furnace, collect the sample, which is Sb2S3@Sb6O 13 @rGO composite material.

[0032] Example 2

[0033] Step 1: Weigh 0.5 mmol of SbCl3, L-cysteine, and L-tartaric acid respectively and dissolve them in a beaker to obtain solution A;

[0034] Step 2: Weigh 3 g of polyethylene polyvinyl pyrrolidone and add it to solution A. After halving, transfer it to a stainless steel reactor and place it in a heating box at 150°C for 12 hours. After cooling in the furnace, collect the antimony sulfide sample.

[0035] Step 3, weighing 0.5 mmol of the antimony sulfide prepared in step 2, placing it in a vacuum tube furnace, sintering it at 500°C for 5 hours in a mixed atmosphere of hydrogen and argon, and then cooling the furnace to obtain an intermediate product, Sb2S3 / Sb composite material;

[0036] Step 4: Continue to weigh the Sb2S3 / Sb composite material prepared in step 3, dissolve it in deionized water, and then perform ultrasonic treatment. Then, mix it with the graphene oxide solution, stir it evenly, and transfer it to a stainless steel reactor for a second hydrothermal reaction. Set the hydrothermal temperature to 150°C for 12 hours. After cooling in the furnace, collect the sample, which is Sb2S3@Sb6O 13 @rGO composite material.

Claims

1. A Sb2S3@Sb6O 13 The preparation method of @rGO composite material is characterized in that: The steps include: S1: Dissolve soluble antimony salt, L-tartaric acid and sulfiding agent in a beaker filled with deionized water to obtain a mixed solution A; S2: adding polyvinyl pyrrolidone to solution A to obtain a mixed solution C; S3: Transfer solution C to a stainless steel reactor for hydrothermal reaction, filter and dry to obtain solid D; S4: placing solid D in a tube furnace, sintering under a gas atmosphere and cooling the furnace to obtain an intermediate product E; S5: The intermediate product E was dissolved in deionized water, sonicated, mixed with the graphene oxide solution, and then transferred to a stainless steel reactor for a second hydrothermal reaction; S6: After the hydrothermal reaction, the solid F is obtained by cooling in the furnace, filtering and drying; S7: After freeze-drying solid F, Sb2S3@Sb6O is obtained. 13 @rGO composite material.

2. Sb2S3@Sb6O according to claim 1 13 The preparation method of @rGO composite material is characterized in that: The solid D is spherical antimony sulfide.

3. Sb2S3@Sb6O according to claim 1 13 The preparation method of @rGO composite material is characterized in that: The antimony salt is one or more of antimony nitrate, antimony bromide, antimony trichloride, antimony sulfide, antimony pentachloride, antimony sulfate, and antimony hydroxide.

4. Sb2S3@Sb6O according to claim 2 13 The preparation method of @rGO composite material is characterized in that: The polyvinyl pyrrolidone is used to modify the shape of the spherical antimony sulfide.

5. Sb2S3@Sb6O according to claim 1 13 The preparation method of @rGO composite material is characterized in that: The vulcanizing agent is one or more of sodium sulfide, thioacetamide and L-cysteine.

6. Sb2S3@Sb6O according to claim 2 13 The preparation method of @rGO composite material is characterized in that: The gas atmosphere of the spherical antimony sulfide in the tube furnace is one or more of N2 / H2, Ar / H2, N2, and Ar.

7. Sb2S3@Sb6O according to claim 1 13 The preparation method of @rGO composite material is characterized in that: The hydrothermal reaction temperature is 100-200°C.

8. Sb2S3@Sb6O according to claim 1 13 The preparation method of @rGO composite material is characterized in that: The sintering time in the tube furnace is 1 to 5 hours.

9. A Sb2S3@Sb6O 13 @rGO composite material, characterized in that The invention is prepared by the preparation method according to any one of claims 1 to 8.

10. A Sb2S3@Sb6O according to claim 9 13 The application of @rGO composite material is characterized by The Sb2S3@Sb6O 13 Application of @rGO composite materials in the field of lithium-ion battery anode materials.

Images