A method for preparing clustered antimony trioxide

Abstract

The present invention relates to the field of inorganic materials, and in particular to a method for preparing clustered antimony trioxide. The method comprises the following steps: adding antimony trichloride to an organic solvent consisting of ethanol and n-butanol, adding a surfactant and mixing, dropping deionized water, and adjusting the pH of the system to 1-2 to obtain a mixed solution. The mixed solution is transferred to a polytetrafluoroethylene-lined autoclave, sealed, heated to 120-150°C, and reacted for 5-10 hours. After returning to room temperature, the pH of the reaction solution is adjusted to 8-9 with an alkaline solution, stirred for 10-60 minutes, and then the precipitate is collected, washed, and dried. The clustered antimony trioxide prepared by the present invention is used as an active material and can significantly improve the electrochemical performance of a lithium-ion battery.

Description

Technical Field

[0001] The present invention relates to the field of inorganic materials, and in particular to a method for preparing clustered antimony trioxide. Background Art

[0002] Antimony trioxide (Sb2O3) possesses unique physical and chemical properties and is widely used in chemical synthesis as a pigment, catalyst, flame retardant, and passivator for petroleum cracking. It also holds great promise in battery manufacturing and thin film processing. The properties of antimony trioxide are closely related to its particle morphology and size, making the preparation of antimony trioxide with different morphologies and particle sizes of great significance. Summary of the Invention

[0003] Purpose of the invention: In order to solve the above technical problems, the present invention proposes a method for preparing clustered antimony trioxide.

[0004] The technical solutions adopted are as follows:

[0005] A method for preparing clustered antimony trioxide is as follows:

[0006] S1: adding antimony trichloride to an organic solvent consisting of ethanol and n-butanol, adding a surfactant and mixing, adding deionized water dropwise and adjusting the pH of the system to 1-2 to obtain a mixed solution;

[0007] S2: Transfer the mixed solution to a polytetrafluoroethylene-lined autoclave, seal it, heat it to 120-150°C, and react for 5-10 hours. After returning to room temperature, adjust the pH of the reaction solution to 8-9 with an alkaline solution, stir it for 10-60 minutes, collect the precipitate, wash it, and dry it.

[0008] Furthermore, the mass ratio of ethanol to n-butanol in the organic solvent is 1-5:1-5.

[0009] Furthermore, the surfactant includes sodium dioctyl sulfosuccinate and Triton X-100.

[0010] Furthermore, the mass ratio of sodium dioctyl sulfosuccinate to Triton X-100 is 1-5:1-5.

[0011] Furthermore, the amount of the surfactant used is 0.1-10% of the mass of antimony trichloride.

[0012] Further, ultrasound is applied while the sealing reaction is taking place.

[0013] Furthermore, the power of ultrasound is 0.1-10W / cm 2 .

[0014] Furthermore, the heating rate is ≤10°C / min.

[0015] Furthermore, the alkaline solution is any one of sodium hydroxide solution, ammonia water, sodium carbonate solution or sodium bicarbonate solution.

[0016] Furthermore, ethanol and deionized water are used in sequence for washing.

[0017] Beneficial effects of the present invention:

[0018] The invention provides a method for preparing clustered antimony trioxide. Under the action of a surfactant, a solvent thermal reaction method is adopted to synthesize nanoscale antimony trioxide with a special cluster structure. The surfactant composed of sodium dioctyl sulfosuccinate and Triton X-100 plays a very important role in the process of preparing the antimony trioxide nanoclusters. On the one hand, it can inhibit the growth and enlargement of individual nanocrystals, and on the other hand, it can limit the continued growth and agglomeration of nanoclusters, thereby making the nanoclusters more uniform in size and better in dispersibility. However, sodium dioctyl sulfosuccinate and Triton X-100 alone do not have this effect. This may be because the coating and spatial protection effects of sodium dioctyl sulfosuccinate or Triton X-100 on crystal nuclei are weak when they are used alone, so that many antimony trioxide particle nanocrystals do not have time to become crystal nuclei of a layered structure, which greatly reduces the chances of them undergoing oriented adsorption and clustering. After testing, the clustered antimony trioxide prepared by the invention can be used as an active material to significantly improve the electrochemical performance of lithium-ion batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a SEM photograph of antimony trioxide prepared in Example 1. DETAILED DESCRIPTION

[0020] Unless otherwise specified, the following examples and comparative examples were conducted in parallel, using the same processing steps and parameters.

[0021] Example 1:

[0022] A method for preparing clustered antimony trioxide:

[0023] 10 g of antimony trichloride was added to an organic solvent consisting of 250 ml of ethanol and 250 ml of n-butanol, stirred evenly, and then a surfactant consisting of 0.25 g of sodium dioctyl sulfosuccinate and 0.25 g of Triton X-100 was added, and the stirring was continued. 500 ml of deionized water was slowly added dropwise, and after the addition was completed, the pH of the system was adjusted to 1 with dilute hydrochloric acid to obtain a mixed solution. The mixed solution was transferred to a high-pressure reactor with a polytetrafluoroethylene liner, and a power of 5 W / cm was applied to the mixed solution. 2 After the high-pressure reactor is sealed, the temperature is raised to 125°C at a rate of 5°C / min for 5 hours. After returning to room temperature, the pH of the reaction solution is adjusted to 8 with ammonia water. After stirring for 30 minutes, the precipitate is collected and washed with ethanol and deionized water in sequence, and finally placed in an oven and dried at 80°C for 10 hours. The microscopic morphology is cluster-shaped with uniform size, the yield is 98.9%, and the purity is ≥99.9%.

[0024] Example 2:

[0025] A method for preparing clustered antimony trioxide:

[0026] 10 g of antimony trichloride was added to an organic solvent consisting of 250 ml of ethanol and 250 ml of n-butanol, stirred evenly, and then a surfactant consisting of 0.25 g of sodium dioctyl sulfosuccinate and 0.25 g of Triton X-100 was added, and the stirring was continued. 500 ml of deionized water was slowly added dropwise, and after the addition was completed, the pH of the system was adjusted to 1 with dilute hydrochloric acid to obtain a mixed solution. The mixed solution was transferred to a high-pressure reactor with a polytetrafluoroethylene liner, and a power of 10 W / cm was applied to the mixed solution. 2 After the high-pressure reactor is sealed, the temperature is raised to 150°C at a rate of 5°C / min for 10 hours. After returning to room temperature, the pH of the reaction solution is adjusted to 8 with ammonia water. After stirring for 60 minutes, the precipitate is collected and washed with ethanol and deionized water in sequence, and finally placed in an oven and dried at 80°C for 10 hours. The microscopic morphology is cluster-shaped with uniform size, the yield is 98.6%, and the purity is ≥99.9%.

[0027] Example 3:

[0028] A method for preparing clustered antimony trioxide:

[0029] 10 g of antimony trichloride was added to an organic solvent consisting of 250 ml of ethanol and 250 ml of n-butanol, stirred evenly, and then a surfactant consisting of 0.25 g of sodium dioctyl sulfosuccinate and 0.25 g of Triton X-100 was added, and the stirring was continued. 500 ml of deionized water was slowly added dropwise, and after the addition was completed, the pH of the system was adjusted to 1 with dilute hydrochloric acid to obtain a mixed solution. The mixed solution was transferred to a polytetrafluoroethylene-lined autoclave, and a power of 1 W / cm was applied to the mixed solution.2 After the high-pressure reactor is sealed, the temperature is raised to 120°C at a rate of 5°C / min for 5 hours. After returning to room temperature, the pH of the reaction solution is adjusted to 8 with ammonia water. After stirring for 10 minutes, the precipitate is collected and washed with ethanol and deionized water in sequence, and finally placed in an oven and dried at 80°C for 10 hours. The microscopic morphology is cluster-shaped with uniform size, the yield is 97.8%, and the purity is ≥99.9%.

[0030] Example 4:

[0031] A method for preparing clustered antimony trioxide:

[0032] 10g of antimony trichloride was added to an organic solvent consisting of 250ml of ethanol and 250ml of n-butanol, and stirred evenly. A surfactant consisting of 0.25g of sodium dioctyl sulfosuccinate and 0.25g of Triton X-100 was added, and stirring was continued. 500ml of deionized water was slowly added dropwise. After the dropwise addition, the pH of the system was adjusted to 1 with dilute hydrochloric acid to obtain a mixed solution. The mixed solution was transferred to an autoclave with a polytetrafluoroethylene liner, and the autoclave was sealed and heated to 125°C at a rate of 5°C / min for 5h. After returning to room temperature, the pH of the reaction solution was adjusted to 8 with ammonia water. After stirring for 30min, the precipitate was collected and washed with ethanol and deionized water in sequence, and finally placed in an oven and dried at 80°C for 10h. The microscopic morphology was cluster-like, but the size uniformity was poor, the yield was 97.7%, and the purity was ≥99.9%.

[0033] Comparative Example 1:

[0034] The preparation method is basically the same as Example 1, except that 0.5 g of Triton X-100 is used instead of the surfactant composed of 0.25 g of sodium dioctyl sulfosuccinate and 0.25 g of Triton X-100. The microscopic morphology is spherical and the size is relatively uniform. The yield is 96.5% and the purity is ≥99.9%.

[0035] Comparative Example 2:

[0036] The present invention is basically the same as Example 1, except that 0.5 g of sodium dioctyl sulfosuccinate is used instead of 0.25 g of sodium dioctyl sulfosuccinate and 0.25 g of Triton X-100 as the surfactant. The microscopic morphology is spherical and the size is uneven. The yield is 97.5% and the purity is ≥99.9%.

[0037] Performance testing:

[0038] ① Antimony trioxide prepared in Example 1 was used as the active material, N-methyl-2-pyrrolidone as the solvent, polyvinylidene fluoride (PVDF) as the binder, and acetylene black as the conductive agent. The active material, binder, and conductive agent were weighed in a mass ratio of 8:1:1. First, the binder was fully dissolved in the solvent in a weighing bottle, and then the mixture of acetylene black and the active material was slowly added. The slurry obtained by stirring was coated on a clean copper foil with a coating machine. The coated copper foil was placed in a vacuum drying oven and dried at 100°C for 24 hours. It was taken out and punched into a circular negative electrode sample with a diameter of 14 mm using a slicer. The sample was placed in a glove box protected by a high argon atmosphere. The sample was used as the working electrode and the metal lithium sheet was used as the positive electrode sheet. LiPF6 / ethylenecarbonated(EC) / dimenthyl Carbonate (DEC) was used as the electrolyte, polypropylene was used as the separator, and a CR2025 button cell was assembled. The battery was assembled in the order of negative electrode cap, negative electrode sheet, electrolyte, separator, electrolyte, positive electrode sheet, gasket, and positive electrode cap. The assembled battery was removed from the glove box, and the positive and negative electrode shells were pressed and sealed with a sealing machine to obtain a CR2025 button cell. The electrochemical performance was tested using a blue electric test system. After three cycles of activation at a low rate of 0.1C, the charge and discharge cycle test was then carried out under 1C conditions. After activation at a rate of 0.1C, the initial charge capacity was 522mAh / g, the initial discharge capacity was 796mAh / g, and the capacity retention rate after 50 cycles at 1C was 83.7%.

[0039] ② Commercially available antimony trioxide (CY-SB20, Jiupeng) was used instead of the antimony trioxide prepared in Example 1 as the active material, and the test in ① was repeated. After activation at a rate of 0.1C, the first charge specific capacity was 401mAh / g, the first discharge specific capacity was 685mAh / g, and the capacity retention rate was 66.4% after 50 cycles at 1C.

[0040] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for preparing clustered antimony trioxide, characterized in that: The details are as follows: S1: adding antimony trichloride to an organic solvent consisting of ethanol and n-butanol, adding a surfactant and mixing, adding deionized water dropwise and adjusting the pH of the system to 1-2 to obtain a mixed solution; S2: The mixed solution is transferred to a polytetrafluoroethylene-lined autoclave, sealed and heated to 120-150°C for reaction for 5-10 hours. After returning to room temperature, the pH of the reaction solution is adjusted to 8-9 with an alkaline solution, stirred for 10-60 minutes, and then the precipitate is collected, washed, and dried. The mass ratio of ethanol to n-butanol in the organic solvent is 1-5:1-5; The surfactant includes sodium dioctyl sulfosuccinate and Triton X-100; The mass ratio of sodium dioctyl sulfosuccinate and Triton X-100 is 1-5:1-5; The amount of the surfactant is 0.1-10% of the mass of antimony trichloride; applying ultrasound while sealing the reaction; The power of ultrasound is 0.1-10W / cm 2 ; The purity of the clustered antimony trioxide is ≥99.9%.

2. The method for preparing clustered antimony trioxide according to claim 1, wherein: Heating rate ≤10℃ / min.

3. The method for preparing clustered antimony trioxide according to claim 1, wherein: The alkaline solution is any one of sodium hydroxide solution, ammonia water, sodium carbonate solution or sodium bicarbonate solution.

4. The method for preparing clustered antimony trioxide according to claim 1, wherein: Wash with ethanol and deionized water in sequence.

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