Preparation method and application of silver tetrafluoroborate

Abstract

The preparation method comprises the following steps: S1, accurately weighing 1.0 mol of silver oxide and 2.0 mol of tetrafluoroboric acid, and respectively dissolving the silver oxide and the tetrafluoroboric acid in a proper amount of deionized water to prepare a solution with the concentration of about 0.1 mol / L; s2, mixing the two solutions according to the volume ratio of 1: 1; reacting to generate white precipitated silver tetrafluoroborate; s3, after the reaction is finished, separating the generated precipitate from the solution by using a centrifugal machine, and repeatedly washing with deionized water until the eluate is neutral; s4, placing the cleaned precipitate in an air dry oven for drying to obtain pure silver tetrafluoroborate powder; the preparation method of the silver tetrafluoroborate has the advantages of simplicity in operation, mild reaction conditions and low cost; the prepared silver tetrafluoroborate is high in purity, shows excellent performance in application in the fields of organic synthesis and electrochemistry, can improve the yield and selectivity of organic reaction and improve the performance of an electrochemical device, and has wide application prospects.

Description

Technical Field

[0001] The present invention belongs to the technical fields of chemical materials science and new energy materials, and specifically relates to a preparation method and application of silver tetrafluoroborate. Background Art

[0002] Silver tetrafluoroborate is a silver salt, and its molecular structure contains silver ions and tetrafluoroborate ions. Tetrafluoroborate compounds have been widely studied due to their excellent chemical stability and good electrical conductivity, and significant progress has been made in many fields such as electrochemistry and catalysis. Silver ions themselves have excellent catalytic properties and are widely used in fields such as organic synthesis, electronic components, and solar cells. The tetrafluoroborate ion, due to its low coordination and high solubility, makes tetrafluoroborate compounds materials with special properties.

[0003] With the global energy structure transforming towards green and sustainable directions, lithium-ion batteries, as important energy storage devices, are playing an increasingly important role in fields such as electric vehicles (EVs), portable electronic products, and large-scale energy storage systems. The electrolyte is an important component of lithium-ion batteries and is directly related to key performance indicators such as the energy density, power density, cycle life, and safety of the batteries. Currently, commonly used lithium salt electrolytes, such as lithium hexafluorophosphate, although having good electrical conductivity and stability, also have some deficiencies, such as being prone to decomposition at high temperatures to produce harmful gases and being sensitive to moisture, resulting in a decline in battery performance. Therefore, finding better lithium salt substitutes has become the focus of attention of scientific researchers.

[0004] Silver tetrafluoroborate, as a potential lithium salt substitute, has the following advantages:

[0005] 1. Excellent electrochemical performance: It has a high ionic conductivity, which can effectively promote the transport of lithium ions between the positive and negative electrodes, thereby improving the overall performance of the battery.

[0006] 2. Good thermal stability: It can maintain stable physical and chemical properties even at relatively high temperatures, which helps to improve the safety of the battery.

[0007] 3. Environmental friendliness: Compared with traditional lithium salts, it has less impact on the environment and conforms to the development trend of green chemistry.

[0008] Secondly, silver tetrafluoroborate plays a unique role in many chemical reactions and industrial applications. In organic synthesis, it is often used as a mild Lewis acid catalyst, which can promote various organic reactions, such as carbon-carbon bond formation reactions and cyclization reactions. In the field of electrochemistry, silver tetrafluoroborate can be used as a key component in electrolytes and participate in the working process of electrochemical devices such as batteries.

[0009] However, the traditional methods for preparing silver tetrafluoroborate have some limitations. For example, some methods may produce a large amount of impurities, affecting the purity of silver tetrafluoroborate, and thus its performance in catalytic and electrochemical applications. In addition, some preparation processes may require complex equipment and harsh reaction conditions, resulting in high production costs and being unfavorable for large-scale production. Therefore, it is of great significance to develop a preparation method for silver tetrafluoroborate that is efficient, low-cost, and can obtain high purity. For this purpose, the present invention proposes a simple and efficient method for preparing silver tetrafluoroborate, aiming to overcome the limitations of the prior art. Summary of the Invention

[0010] The purpose of the present invention is to provide a method for preparing silver tetrafluoroborate and its application to solve the problems raised in the above background technology.

[0011] To achieve the above purpose, the present invention provides the following technical solution: A method for preparing silver tetrafluoroborate, the specific steps include: S1: Accurately weigh 1.0 mol of silver oxide and 2.0 mol of tetrafluoroboric acid, and dissolve them in appropriate amounts of deionized water respectively to prepare solutions with a concentration of about 0.1 mol / L;

[0012] S2: Mix the above two solutions in a volume ratio of 1:1; during this process, Ag + reacts with BF4 - by double decomposition reaction to form silver tetrafluoroborate as a white precipitate;

[0013] S3: After the reaction is completed, use a centrifuge to separate the generated precipitate from the solution, and wash it repeatedly with deionized water several times until the wash liquor is neutral;

[0014] S4: Place the washed precipitate in a forced-air drying oven, and after complete drying, finally obtain pure silver tetrafluoroborate powder.

[0015] Preferably, in S1, when preparing the two solutions, it is necessary to maintain at 15 °C and a stirring speed of 300 rpm.

[0016] Preferably, in S2, the solution mixing reaction needs to control the pH value at 7 and stir the reaction at room temperature for 1 - 1.5 h.

[0017] Preferably, in S4, the precipitate needs to be dried in a forced-air drying oven at 50 - 60 °C for 8 - 12 hours.

[0018] An application of silver tetrafluoroborate prepared by the above method, the application of silver tetrafluoroborate as a catalyst in organic synthesis can improve the reaction yield, reduce the occurrence of side reactions, and improve the selectivity of the target product.

[0019] The application of silver tetrafluoroborate prepared by the above method, the application of silver tetrafluoroborate in the field of electrochemistry. Adding an appropriate amount of silver tetrafluoroborate to the electrolyte of a lithium-ion battery can improve the charge and discharge performance of the battery, reduce the polarization phenomenon of the battery, and improve the energy efficiency of the battery; in a supercapacitor, silver tetrafluoroborate as an electrolyte additive can increase the interfacial stability between the electrode material and the electrolyte, and improve the capacitance retention rate and cycle life of the supercapacitor.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] The preparation method of silver tetrafluoroborate of the present invention has the advantages of simple operation, mild reaction conditions and low cost; the prepared silver tetrafluoroborate has high purity, shows excellent performance in the applications in the fields of organic synthesis and electrochemistry, can improve the yield and selectivity of organic reactions, and improve the performance of electrochemical devices, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the preparation process flow of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0024] Example 1

[0025] Please refer to Figure 1 , the present invention provides a technical solution: a method for preparing silver tetrafluoroborate, the specific steps include: S1: Accurately weigh 1.0 mol of silver oxide and 2.0 mol of tetrafluoroboric acid, dissolve them in appropriate amounts of deionized water respectively, and keep stirring evenly under the conditions of a temperature of 15 °C and a stirring speed of 300 rpm to prepare solutions with a concentration of about 0.1 mol / L;

[0026] S2: Mix the above two solutions in a volume ratio of 1:1; it is necessary to control the pH value to 7, and stir and react at room temperature for 1 - 1.5 h; during this process, Ag + and BF4 - undergo a metathesis reaction to form white precipitate silver tetrafluoroborate;

[0027] S3: After the reaction is completed, use a centrifuge to separate the generated precipitate from the solution, and wash it repeatedly with deionized water several times until the washing liquid is neutral;

[0028] S4: Place the washed precipitate in a forced-air drying oven and dry it at 50 - 60 °C for 8 - 12 hours; after complete drying, finally obtain pure silver tetrafluoroborate powder.

[0029] The prepared silver tetrafluoroborate was structurally characterized by X-ray diffraction (XRD). The XRD pattern showed characteristic peaks consistent with the standard crystal structure of silver tetrafluoroborate, indicating that the prepared substance had high purity and the correct crystal structure. The elemental composition was analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES), and the results showed that the contents of silver, boron, and fluorine were consistent with the theoretical values, and the impurity content was less than 1%.

[0030] Example 2

[0031] Application of silver tetrafluoroborate in the electrolyte of lithium-ion batteries

[0032] 1. Preparation of electrolyte solution: Dissolve a certain amount of silver tetrafluoroborate in a mixed solvent of ethylene carbonate (EC) and dimethyl carbonate (DMC) (volume ratio 1:1) to prepare an electrolyte solution with a concentration of 1 mol / L.

[0033] 2. Battery assembly and testing: Using the standard CR2032 coin cell model, with graphite as the negative electrode material and LiFePO4 as the positive electrode material, assemble a half-cell structure. Then, perform charge-discharge tests on this battery at room temperature to investigate its cycling performance and rate performance.

[0034] The experimental results showed that the lithium-ion battery using the silver tetrafluoroborate prepared by the present invention as the electrolyte exhibited excellent electrochemical performance:

[0035] 1. At a low current density of 0.1C, the initial discharge capacity reached 160 mAh / g, and after 100 charge-discharge cycles, the capacity retention rate was still as high as over 90%;

[0036] 2. When the current density increased to 1C, the battery could still maintain a discharge capacity of over 130 mAh / g, indicating its good rate performance;

[0037] 3. In addition, when the battery was working in a high-temperature (55 °C) environment, no obvious capacity decay phenomenon was observed, demonstrating the excellent thermal stability of the silver tetrafluoroborate electrolyte.

[0038] Example 3

[0039] Application of silver tetrafluoroborate in the Diels-Alder reaction

[0040] In a three-necked flask equipped with a magnetic stir bar, a thermometer, and a reflux condenser, 10 mmol of cyclopentadiene, 10 mmol of methyl acrylate, and 0.1 mmol of silver tetrafluoroborate were added, and then 20 mL of toluene was added as a solvent. The reaction was stirred at room temperature for 24 hours. After the reaction was completed, the product was analyzed by gas chromatography-mass spectrometry (GC-MS), and the yield of the Diels-Alder reaction product reached 90%.

[0041] Although the embodiments of the present invention have been shown and described, see the above detailed description, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A preparation method of silver tetrafluoroborate, characterized in that: The specific steps include: S1: Accurately weigh 1.0 mol of silver oxide and 2.0 mol of tetrafluoroboric acid, dissolve them separately in appropriate amounts of deionized water, and prepare solutions with a concentration of approximately 0.1 mol / L. S2: Mix the above two solutions in a volume ratio of 1:1; during this process, Ag + reacts with BF4 - to undergo a metathesis reaction to form silver tetrafluoroborate as a white precipitate; S3: After the reaction, use a centrifuge to separate the generated precipitate from the solution, and wash it repeatedly with deionized water several times until the wash liquid is neutral. S4: Place the washed precipitate in a blast drying oven. After complete drying, finally obtain pure silver tetrafluoroborate powder.

2. The preparation method of silver tetrafluoroborate according to claim 1, characterized in that: In S1, when preparing the two solutions, it is necessary to maintain the temperature at 15 °C and the stirring speed at 300 rpm.

3. The preparation method of silver tetrafluoroborate according to claim 1, characterized in that: In S2, for the mixed reaction of the solutions, the pH value needs to be controlled at 7, and the reaction is stirred at room temperature for 1 - 1.5 h.

4. The preparation method of silver tetrafluoroborate according to claim 1, characterized in that: In S4, the precipitate in the blast drying oven needs to be dried at 50 - 60 °C for 8 - 12 hours.

5. Use of silver tetrafluoroborate prepared by the method according to any one of claims 1 to 4, characterized in that: The application of silver tetrafluoroborate as a catalyst in organic synthesis can improve the reaction yield, reduce the occurrence of side reactions, and improve the selectivity of the target product.

6. Use of silver tetrafluoroborate prepared by the method according to any one of claims 1-4, characterized in that: The application of silver tetrafluoroborate in the field of electrochemistry. Adding an appropriate amount of silver tetrafluoroborate to the electrolyte of a lithium-ion battery can improve the charge and discharge performance of the battery, reduce the polarization phenomenon of the battery, and improve the energy efficiency of the battery; in a supercapacitor, silver tetrafluoroborate as an electrolyte additive can increase the interfacial stability between the electrode material and the electrolyte, and improve the capacitance retention rate and cycle life of the supercapacitor.

Images