A bismuth-based halosulfide, a preparation method thereof, a negative electrode sheet, and a battery
Bi4Cl2S5 was prepared by a simple one-step solvothermal method, which solved the preparation problem in the existing technology, provided conditions for its research, and showed good stability and large specific capacity in lithium batteries.
Patent Information
- Application Number
- CN202410046856.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-11
- Publication Date
- 2026-11-03
- Estimated Expiration
- 2044-01-11
AI Technical Summary
Existing technologies make it difficult to prepare Bi4Cl2S5 easily, which limits research on the properties and applications of this substance.
Bi4Cl2S5 was prepared by a simple one-step solvothermal method, which involves reacting bismuth chloride and a sulfur source in an organic solvent at 180-200℃ for 0.5-12 h.
The high-purity preparation of Bi4Cl2S5 was achieved, providing favorable conditions for its property study, and it exhibited good stability and large specific capacity in lithium batteries.
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Figure CN118005076B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of halide preparation technology, and in particular to a bismuth-based halide sulfide and its preparation method, a negative electrode sheet, and a battery. Background Technology
[0002] Bi-SX (X = Cl, Br, I) compounds, belonging to halide materials, have attracted widespread attention in the field of materials science in recent years. These compounds are primarily studied due to their unique physical and chemical properties, showing great potential for applications, especially in optoelectronic materials and energy storage. Examples of such materials include BiSI and Bi... 13 S 18 X2 possesses a low bandgap energy, giving it excellent performance in visible light absorption and thus promising applications in solar cells, visible light photocatalysis, and photodetectors. Furthermore, Bi... 13 S 18 Due to their excellent thermoelectric properties, X2 is also used in thermoelectric power generation devices, especially those requiring the conversion of waste heat into electricity (such as automotive emissions and industrial waste heat recovery). Simultaneously, their excellent biocompatibility and low toxicity make them potential applications in the biomedical field, such as drug delivery and medical imaging technologies. These application examples illustrate the broad potential and diverse applications of Bi-SX compounds in energy, environment, and biomedicine. With future technological advancements and further research, the application scope of these materials is expected to expand further. However, Bi4Cl2S5, as a member of this class of compounds, was prepared in 1979 via vapor-phase growth. The extremely demanding preparation conditions have greatly limited research on this substance, and to date, research on its properties and applications remains largely unexplored.
[0003] Therefore, existing technologies still need to be improved and developed. Summary of the Invention
[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a bismuth-based halide sulfide and its preparation method, a negative electrode sheet, and a battery, aiming to provide a simple method for preparing bismuth-based halide sulfide Bi4Cl2S5 so as to conduct relevant research on this substance.
[0005] The technical solution of the present invention is as follows:
[0006] In a first aspect, the present invention provides a method for preparing bismuth-based halosulfides, wherein the method for preparing bismuth-based halosulfides includes the following steps:
[0007] Bismuth chloride and a sulfur source were added to an organic solvent and reacted at 180-200℃ for 0.5-12 h with stirring to obtain a bismuth-based halosulfide with the chemical formula Bi4Cl2S5.
[0008] The ratio of bismuth chloride, sulfur in the sulfur source, and organic solvent is 5 mmol: 2 mmol: (15-25) mL.
[0009] Optionally, the sulfur source includes thiourea and / or thioacetamide.
[0010] Optionally, the organic solvent includes acetone.
[0011] Optionally, the reaction can be carried out for 4-12 hours.
[0012] Optionally, the stirring speed is 20-50 rpm.
[0013] In a second aspect, the present invention provides a bismuth-based halosulfide, wherein the bismuth-based halosulfide is prepared by the preparation method described above, and the bismuth-based halosulfide is a Bi4Cl2S5 micron rod.
[0014] A third aspect of the present invention provides a negative electrode sheet, wherein the negative electrode sheet includes a negative current collector and an active layer located on the negative current collector, the active layer comprising the bismuth-based halide sulfide of the present invention as described above.
[0015] Optionally, the active layer further includes a conductive agent, which includes at least one of carbon black, carbon nanotubes, and graphene.
[0016] Optionally, the active layer further includes an adhesive, which includes at least one of sodium alginate and sodium carboxymethyl cellulose.
[0017] In a fourth aspect, the present invention provides a battery comprising the negative electrode sheet of the present invention as described above.
[0018] Beneficial Effects: This invention employs a simple one-step solvothermal method, adding bismuth chloride and a sulfur source to an organic solvent and reacting at 180-200℃ for 0.5-12 hours with stirring to prepare bismuth-based halosulfides Bi4Cl2S5. This provides favorable conditions for related research on bismuth-based halosulfides Bi4Cl2S5. Furthermore, bismuth-based halosulfides Bi4Cl2S5, when used as a negative electrode material in lithium batteries, exhibits good stability and a large specific capacity. Attached Figure Description
[0019] Figure 1 The images show the XRD patterns of the bismuth-based halosulfides prepared in Examples 1-5 of this invention.
[0020] Figure 2 (a) is the FESEM image of the bismuth-based halosulfide prepared in Example 2 of the present invention, (b) is the FESEM image of the bismuth-based halosulfide prepared in Example 3 of the present invention, (c) is the FESEM image of the bismuth-based halosulfide prepared in Example 4 of the present invention, and (d) is the FESEM image of the bismuth-based halosulfide prepared in Example 5 of the present invention.
[0021] Figure 3 The image shows the TGA-DTA curve of the bismuth-based halosulfide prepared in Example 5 of this invention.
[0022] Figure 4 This is the ultraviolet-visible-near-infrared absorption spectrum of the bismuth-based halosulfide prepared in Example 5 of the present invention.
[0023] Figure 5 The image shows the XRD pattern of the product prepared in Comparative Example 1.
[0024] Figure 6 The image shows the XRD pattern of the product prepared in Comparative Example 2.
[0025] Figure 7 The images show the XRD patterns of the products prepared in Comparative Examples 3 and 4.
[0026] Figure 8 The image shows the XRD pattern of the product prepared in Comparative Example 5.
[0027] Figure 9 The image shows the XRD pattern of the product prepared in Comparative Example 6.
[0028] Figure 10 This is a graph showing the charge-discharge cycle test results of the button battery prepared in Example 10 of the present invention. Detailed Implementation
[0029] This invention provides a bismuth-based halosulfide, its preparation method, a negative electrode, and a battery. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.
[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
[0031] This invention provides a method for preparing bismuth-based halosulfides, wherein the method for preparing bismuth-based halosulfides includes the following steps:
[0032] Bismuth chloride and a sulfur source are added to an organic solvent and reacted at 180-200℃ for 0.5-12 hours under stirring (specifically in a homogeneous reactor) to obtain a bismuth-based halosulfide with the chemical formula Bi4Cl2S5.
[0033] The ratio of bismuth chloride, sulfur in the sulfur source, and organic solvent is 5 mmol: 2 mmol: (15-25) mL.
[0034] This invention employs a simple one-step solvothermal method, adding bismuth chloride and a sulfur source to an organic solvent and reacting under stirring conditions at 180-200℃ for 0.5-12 hours to prepare bismuth-based halosulfides Bi4Cl2S5. This provides favorable conditions for related research on bismuth-based halosulfides Bi4Cl2S5. Furthermore, bismuth-based halosulfides Bi4Cl2S5, when used as a negative electrode material in lithium batteries, exhibits good stability and a large specific capacity, filling a gap in the application of Bi4Cl2S5.
[0035] In this embodiment of the invention, the ratio of bismuth chloride, sulfur in the sulfur source, to the organic solvent (i.e., the concentration of reactants) is crucial, as the reaction is highly sensitive to reactant concentrations. The Bi₄Cl₂S₅ phase is only produced when the ratio of bismuth chloride, sulfur in the sulfur source, to the organic solvent is within the range of 5 mmol:2 mmol:(15-25) mL. When the ratio of bismuth chloride, sulfur in the sulfur source, to the organic solvent is not within this range, other phases (such as BiSCl, Bi...) will be produced. 19 S 27 Cl3, etc. Specifically, when the reactant concentration increases (i.e., the solvent volume decreases), the reaction produces BiSCl; when the reactant concentration decreases (i.e., the solvent volume increases), Bi is produced. 19 S 27 Cl3. Additionally, when the molar ratio of sulfur to bismuth chloride in the sulfur source decreases (the molar ratio of sulfur to bismuth chloride is less than 2:5), the reaction produces BiSCl; when the molar ratio of sulfur to bismuth chloride in the sulfur source is excessive (the molar ratio of sulfur to bismuth chloride is greater than 2:5), the reaction produces Bi. 19 S 27 Cl3.
[0036] In this embodiment, as an example, the reaction temperature can be 180℃, 182℃, 184℃, 185℃, 186℃, 188℃, 190℃, 192℃, 194℃, 195℃, 195℃, 196℃, 198℃, or 200℃, etc., and the reaction time can be 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, or 12h, etc.
[0037] In some embodiments, the sulfur source comprises thiourea and / or thioacetamide. That is, the sulfur source is thiourea, or the sulfur source is thioacetamide, or the sulfur source is a mixture of thiourea and thioacetamide.
[0038] In some embodiments, the organic solvent includes, but is not limited to, acetone.
[0039] In some embodiments, the reaction is carried out for 4-12 hours. In some specific embodiments, the reaction is carried out for 8-12 hours. This ensures that the obtained product Bi4Cl2S5 has strong crystallinity.
[0040] In some embodiments, the stirring speed is 20-50 rpm. For example, the stirring speed is 20 rpm, 30 rpm, 40 rpm, or 50 rpm.
[0041] This invention also provides a bismuth-based halosulfide, wherein the bismuth-based halosulfide is prepared using the preparation method described above in this invention, and the bismuth-based halosulfide is a Bi4Cl2S5 microrod. In some specific embodiments, the diameter of the Bi4Cl2S5 microrod is 100-300 nm.
[0042] This invention also provides a negative electrode sheet, wherein the negative electrode sheet includes a negative electrode current collector and an active layer located on the negative electrode current collector, the active layer including the bismuth-based halide sulfide described above in this invention embodiment.
[0043] In some embodiments, the negative current collector includes, but is not limited to, copper foil, nickel foil, and titanium foil.
[0044] In some embodiments, the active layer further includes a conductive agent, which includes, but is not limited to, at least one of carbon black, carbon nanotubes, and graphene. The conductive agent facilitates lithium-ion transport and improves the rate performance of the battery containing the negative electrode.
[0045] In some embodiments, the active layer further includes a binder, which includes, but is not limited to, at least one of sodium alginate and sodium carboxymethyl cellulose. The addition of the binder facilitates the loading of the active layer onto the negative electrode current collector, and also promotes the tight bonding of bismuth-based halide sulfides and the conductive agent, thereby facilitating lithium-ion transport.
[0046] This invention also provides a battery, which includes the negative electrode sheet described above. In some specific embodiments, the battery is a lithium-ion battery, which has a large capacity and good cycle stability.
[0047] The following detailed description uses specific examples.
[0048] Example 1
[0049] This embodiment provides a method for preparing bismuth-based halosulfides, including the following steps:
[0050] 5 mmol of bismuth chloride (BiCl3) and 2 mmol of thiourea (CH4N2S) were placed in a 50 mL polytetrafluoroethylene autoclave, and then 20 mL of acetone was added. The mixture was magnetically stirred at room temperature for two hours to obtain a mixture.
[0051] The mixture was placed in a homogeneous reactor and reacted at 30 rpm and 190°C for 0.5 h. The product was separated by filtration and then washed three times with acetone. The obtained black solid was placed in a drying oven and dried at 60°C for 12 h to obtain micron rod-shaped bismuth-based halide sulfide Bi4Cl2S5.
[0052] Example 2
[0053] This embodiment provides a method for preparing bismuth-based halosulfides, including the following steps:
[0054] 5 mmol of bismuth chloride (BiCl3) and 2 mmol of thiourea (CH4N2S) were placed in a 50 mL polytetrafluoroethylene autoclave, and then 20 mL of acetone was added. The mixture was magnetically stirred at room temperature for two hours to obtain a mixture.
[0055] The mixture was placed in a homogeneous reactor and reacted at 30 rpm and 190°C for 1 hour. The product was separated by filtration and then washed three times with acetone. The obtained black solid was placed in a drying oven and dried at 60°C for 12 hours to obtain micron rod-shaped bismuth-based halide sulfide Bi4Cl2S5.
[0056] Example 3
[0057] This embodiment provides a method for preparing bismuth-based halosulfides, including the following steps:
[0058] 5 mmol of bismuth chloride (BiCl3) and 2 mmol of thiourea (CH4N2S) were placed in a 50 mL polytetrafluoroethylene autoclave, and then 20 mL of acetone was added. The mixture was magnetically stirred at room temperature for two hours to obtain a mixture.
[0059] The mixture was placed in a homogeneous reactor and reacted at 30 rpm and 190°C for 2 hours. The product was separated by filtration and then washed three times with acetone. The obtained black solid was placed in a drying oven and dried at 60°C for 12 hours to obtain micron rod-shaped bismuth-based halide sulfide Bi4Cl2S5.
[0060] Example 4
[0061] This embodiment provides a method for preparing bismuth-based halosulfides, including the following steps:
[0062] 5 mmol of bismuth chloride (BiCl3) and 2 mmol of thiourea (CH4N2S) were placed in a 50 mL polytetrafluoroethylene autoclave, and then 20 mL of acetone was added. The mixture was magnetically stirred at room temperature for two hours to obtain a mixture.
[0063] The mixture was placed in a homogeneous reactor and reacted at 30 rpm and 190°C for 4 hours. The product was separated by filtration and then washed three times with acetone. The obtained black solid was placed in a drying oven and dried at 60°C for 12 hours to obtain micron rod-shaped bismuth-based halide sulfide Bi4Cl2S5.
[0064] Example 5
[0065] This embodiment provides a method for preparing bismuth-based halosulfides, including the following steps:
[0066] 5 mmol of bismuth chloride (BiCl3) and 2 mmol of thiourea (CH4N2S) were placed in a 50 mL polytetrafluoroethylene autoclave, and then 20 mL of acetone was added. The mixture was magnetically stirred at room temperature for two hours to obtain a mixture.
[0067] The mixture was placed in a homogeneous reactor and reacted at 30 rpm and 190°C for 12 h. The product was separated by filtration and then washed three times with acetone. The obtained black solid was placed in a drying oven and dried at 60°C for 12 h to obtain micron rod-shaped bismuth-based halide sulfide Bi4Cl2S5.
[0068] Example 6
[0069] This embodiment provides a method for preparing bismuth-based halosulfides, including the following steps:
[0070] 5 mmol of bismuth chloride (BiCl3) and 2 mmol of thiourea (CH4N2S) were placed in a 50 mL polytetrafluoroethylene autoclave, and then 15 mL of acetone was added. The mixture was magnetically stirred for two hours at room temperature to obtain a mixture.
[0071] The mixture was placed in a homogeneous reactor and reacted at 30 rpm and 200°C for 12 h. The product was separated by filtration and then washed three times with acetone. The obtained black solid was placed in a drying oven and dried at 60°C for 12 h to obtain micron rod-shaped bismuth-based halide sulfide Bi4Cl2S5.
[0072] Example 7
[0073] This embodiment provides a method for preparing bismuth-based halosulfides, including the following steps:
[0074] 5 mmol of bismuth chloride (BiCl3) and 2 mmol of thioacetamide were placed in a 50 mL polytetrafluoroethylene autoclave, and then 25 mL of acetone was added. The mixture was magnetically stirred for two hours at room temperature to obtain a mixture.
[0075] The mixture was placed in a homogeneous reactor and reacted at 30 rpm and 200°C for 12 h. The product was separated by filtration and then washed three times with acetone. The obtained black solid was placed in a drying oven and dried at 60°C for 12 h to obtain micron rod-shaped bismuth-based halide sulfide Bi4Cl2S5.
[0076] Example 8
[0077] This embodiment provides a method for preparing bismuth-based halosulfides, including the following steps:
[0078] 5 mmol of bismuth chloride (BiCl3) and 2 mmol of thiourea (CH4N2S) were placed in a 50 mL polytetrafluoroethylene autoclave, and then 15 mL of acetone was added. The mixture was magnetically stirred for two hours at room temperature to obtain a mixture.
[0079] The mixture was placed in a homogeneous reactor and reacted at 30 rpm and 180°C for 12 h. The product was separated by filtration and then washed three times with acetone. The obtained black solid was placed in a drying oven and dried at 60°C for 12 h to obtain micron rod-shaped bismuth-based halide sulfide Bi4Cl2S5.
[0080] Example 9
[0081] This embodiment provides a method for preparing bismuth-based halosulfides, including the following steps:
[0082] 5 mmol of bismuth chloride (BiCl3) and 2 mmol of thiourea (CH4N2S) were placed in a 50 mL polytetrafluoroethylene autoclave, and then 25 mL of acetone was added. The mixture was magnetically stirred at room temperature for two hours to obtain a mixture.
[0083] The mixture was placed in a homogeneous reactor and reacted at 30 rpm and 180°C for 12 h. The product was separated by filtration and then washed three times with acetone. The obtained black solid was placed in a drying oven and dried at 60°C for 12 h to obtain micron rod-shaped bismuth-based halide sulfide Bi4Cl2S5.
[0084] test:
[0085] (1) The products from Examples 1-9 were subjected to X-ray diffraction (XRD) tests, and the XRD results of the products from Examples 1-5 were as follows: Figure 1 As shown, Bi4Cl2S5 can be prepared by the methods in Examples 1-5. However, with the extension of reaction time, the crystallinity of Bi4Cl2S5 gradually increases, while the impurity peaks disappear. When the reaction time exceeds 4 hours, Bi4Cl2S5 with higher purity can be obtained. The XRD patterns of the products in Examples 6-9 are similar to those in Example 5.
[0086] (2) The products in Examples 2-5 were tested using field emission scanning electron microscopy (FESEM), and the results are as follows: Figure 2 As shown in (a)-(d), it can be seen that the rod-shaped product obtained after 1 hour of reaction is relatively short, and the micron-sized rod-shaped crystals gradually grow larger with the extension of reaction time. After 12 hours of reaction, Bi4Cl2S5 micron-shaped rods with diameters of 100-300 nm and lengths of tens of micrometers were obtained.
[0087] (3) The TGA-DTA curve of Bi4Cl2S5 prepared in Example 5 is as follows: Figure 3 As shown in the figure, Bi4Cl2S5 has good stability at room temperature, but begins to decompose at 285℃, accompanied by an exothermic reaction.
[0088] (4) The UV-Vis-NIR absorption spectrum of Bi4Cl2S5 prepared in Example 5 is as follows: Figure 4 As shown, it has strong absorption in the ultraviolet-visible-near-infrared region.
[0089] Comparative Example 1
[0090] Place 5 mmol of bismuth chloride (BiCl3) and 2 mmol of thiourea (CH4N2S) in a 50 mL polytetrafluoroethylene autoclave, then add 30 mL or 40 mL of acetone, and stir magnetically for two hours at room temperature to obtain a mixture.
[0091] The mixture was placed in a homogeneous reactor and reacted at 30 rpm and 190°C for 12 hours. The product was separated by suction filtration, then washed three times alternately with acetone. The resulting black solid was placed in a drying oven and dried at 60°C for 12 hours. The product obtained is as follows. Figure 5 As shown, under the condition of 30 mL acetone, the products obtained are Bi4Cl2S5 and Bi. 19 S 27 Cl3, when dissolved in 40 mL of acetone, yields Bi as the product. 19 S 27 Cl3.
[0092] Comparative Example 2
[0093] Place 5 mmol of bismuth chloride (BiCl3) and 2 mmol of thiourea (CH4N2S) in a 50 mL polytetrafluoroethylene autoclave, then add 5 mL or 10 mL of acetone, and stir magnetically for two hours at room temperature to obtain a mixture.
[0094] The mixture was placed in a homogeneous reactor and reacted at 30 rpm and 190°C for 12 hours. The product was separated by suction filtration, then washed three times alternately with acetone. The resulting black solid was placed in a drying oven and dried at 60°C for 12 hours. The product obtained is as follows. Figure 6 As shown, under 5 mL acetone conditions, the product obtained is a single-phase BiSCl, while under 10 mL acetone conditions, two products, BiSCl and Bi4Cl2S5, are obtained.
[0095] Comparative Example 3
[0096] 5 mmol of bismuth chloride (BiCl3) and 1 mmol of thiourea (CH4N2S) were placed in a 50 mL polytetrafluoroethylene autoclave, and then 20 mL of acetone was added. The mixture was magnetically stirred for two hours at room temperature to obtain a mixture.
[0097] The mixture was placed in a homogeneous reactor and reacted at 30 rpm and 190°C for 12 hours. The product was separated by suction filtration, then washed three times alternately with acetone. The resulting black solid was placed in a drying oven and dried at 60°C for 12 hours. The product obtained is as follows. Figure 7 As shown (see) Figure 7 The curve corresponding to 5:1 in the figure is specifically BiSCl.
[0098] Comparative Example 4
[0099] 5 mmol of bismuth chloride (BiCl3) and 4 mmol of thiourea (CH4N2S) were placed in a 50 mL polytetrafluoroethylene autoclave, and then 20 mL of acetone was added. The mixture was magnetically stirred for two hours at room temperature to obtain a mixture.
[0100] The mixture was placed in a homogeneous reactor and reacted at 30 rpm and 190°C for 12 hours. The product was separated by suction filtration, then washed three times alternately with acetone. The resulting black solid was placed in a drying oven and dried at 60°C for 12 hours. The product obtained is as follows. Figure 7 As shown (see) Figure 7 The curve corresponding to 5:4 in the figure), specifically Bi 19 S 27 Cl3.
[0101] Comparative Example 5
[0102] 5 mmol of bismuth chloride (BiCl3) and 2 mmol of thiourea (CH4N2S) were placed in a 50 mL polytetrafluoroethylene autoclave, and then 20 mL of acetone was added. The mixture was magnetically stirred at room temperature for two hours to obtain a mixture.
[0103] The mixture was placed in a homogeneous reactor and reacted at 30 rpm and 210°C or 220°C for 12 hours. The product was separated by suction filtration, then washed three times alternately with acetone. The obtained black solid was placed in a drying oven and dried at 60°C for 12 hours. The product is shown below. Figure 8 As shown, the product obtained at 210℃ is Bi. 19 S 27 Cl3, when heated to 220℃, yields Bi2S3 as the product.
[0104] Comparative Example 6
[0105] 5 mmol of bismuth chloride (BiCl3) and 2 mmol of thiourea (CH4N2S) were placed in a 50 mL polytetrafluoroethylene autoclave, and then 20 mL of acetone was added. The mixture was magnetically stirred at room temperature for two hours to obtain a mixture.
[0106] The mixture was placed in a homogeneous reactor and reacted at 30 rpm and 140°C, 160°C, or 180°C for 12 hours. The product was separated by suction filtration, then washed three times alternately with acetone. The obtained black solid was placed in a drying oven and dried at 60°C for 12 hours. The product is shown below. Figure 9 As shown, at 140℃ and 160℃, the products obtained are Bi4Cl2S5 and impurity phases, with very low crystallinity. At 180℃, the product obtained is mainly BiSCl, with a small amount of impurity phase.
[0107] Example 10
[0108] Bi4Cl2S5 (prepared in Example 5), carbon black, and sodium alginate were mixed in a mass ratio of 7:2:1, and an appropriate amount of water was added. The mixture was stirred at room temperature for 12 hours to obtain a slurry.
[0109] The slurry was applied onto copper foil using a surgical scalpel method; then it was placed in a vacuum oven and dried at 100°C for 12 hours to obtain the negative electrode sheet.
[0110] The negative electrode sheet was assembled into a button cell for performance testing. Using the negative electrode sheet as the positive electrode and the lithium metal sheet as the negative electrode, the battery was assembled using a CR2023 button cell casing. The specific steps are as follows:
[0111] The cells are assembled in the following order: positive electrode shell, negative electrode sheet, glass fiber separator, lithium metal sheet, and negative electrode shell. An electrolyte (LiPF6) is added dropwise to obtain a button cell.
[0112] Charge-discharge cycle tests were conducted at a current density of 0.1 A / g between 0 and 3 V, and the results were as follows: Figure 10 The cycling curves shown indicate that Bi4Cl2S5 exhibits good capacity and cycling stability. The initial specific capacity of Bi4Cl2S5 was 774 mAh / g, and after 260 cycles, it still maintained a specific capacity of 612 mAh / g, with a capacity retention of 79%.
[0113] In summary, this invention provides a bismuth-based halosulfide, its preparation method, an anode material, and a battery. This invention employs a simple one-step solvothermal method, adding bismuth chloride and a sulfur source to an organic solvent and reacting under stirring conditions at 180-200°C for 0.5-12 hours to prepare the bismuth-based halosulfide Bi4Cl2S5. This provides favorable conditions for further research on bismuth-based halosulfide Bi4Cl2S5. Furthermore, bismuth-based halosulfide Bi4Cl2S5, when used as an anode material in lithium batteries, exhibits good stability and a large specific capacity.
[0114] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.
Claims
1. A method for preparing bismuth-based halosulfides, characterized in that, The method for preparing the bismuth-based halosulfide includes the following steps: Bismuth chloride and a sulfur source were added to an organic solvent and reacted at 190-200℃ for 0.5-12 h with stirring to obtain a bismuth-based halosulfide with the chemical formula Bi4Cl2S5. The ratio of bismuth chloride, sulfur in the sulfur source, and organic solvent is 5 mmol: 2 mmol: (15-25) mL; The sulfur source includes thiourea and / or thioacetamide; The organic solvent includes acetone.
2. The preparation method according to claim 1, characterized in that, The reaction time is 4-12 hours.
3. The preparation method according to claim 1, characterized in that, The stirring speed is 20-50 rpm.