KR102666044B1 - Mass Production Method of Metal bis(fluorosulfonyl)imide - Google Patents

Abstract

The present invention relates to a method for mass production of bis(fluorosulfonyl)imide metal salt. More specifically, the present invention relates to a method for mass production of bis(fluorosulfonyl)imide metal salt, which is prepared by mixing bis(fluorosulfonyl)imide represented by Formula 1 as a starting material with a metallization reagent in powder form. By reacting to prepare an aqueous solution of the bis(fluorosulfonyl)imide metal salt represented by Formula 2, and using a suitable concentrator/dryer, bis(fluorosulfonyl)imide metal salt powder represented by Formula 2 was prepared according to the method for producing the bis(fluorosulfonyl)imide metal salt powder represented by Formula 2. will be.
The manufacturing method according to the present invention reacts the bis(fluorosulfonyl)imide compound directly with a powdered metallization reagent without a solvent, thereby generating no related waste, so unlike the prior art, bis(fluorosulfonyl)imide compound is environmentally friendly. Imide metal salt can be manufactured. By quickly concentrating only a small amount of water (about 10% by weight) generated during the reaction and drying the product, high yield and high purity bis(fluorosulfonyl)imide metal salt can be produced in large quantities in an environmentally friendly manner. can be produced

Description

Mass Production Method of Metal bis(fluorosulfonyl)imide}

The present invention relates to a novel production method of bis(fluorosulfonyl)imide metal salt, and more specifically, to a method of producing bis(fluorosulfonyl)imide or ammonium bis(fluorosulfonyl)imide salt as a starting material. It relates to an economical method for producing bis(fluorosulfonyl)imide metal salts very efficiently and in large quantities by reacting with a metalizing reagent, concentrating, and drying.

Recently, the need for high-performance secondary batteries has increased with the commercialization of various mobile devices, and with the commercialization of electric vehicles and hybrid electric vehicles and the development of electric storage devices, secondary batteries with performance such as high output, high energy density, and high discharge voltage have been increasing. A battery was needed.

Among the electrolyte compositions suitable for this, the importance of lithium salt is emerging. Accordingly, the need to economically produce lithium bis(fluorosulfonyl)imide salt has emerged.

Lithium bis(fluorosulfonyl)imide salt has advantages over other lithium salt compounds such as lithium hexafluorophosphate due to its advantages such as high thermal stability, high electrical conductivity, low corrosion, excellent low-temperature performance, and efficient film formation on the anode and cathode. There are a lot of these.

Recently, electric vehicles have been in the spotlight as an eco-friendly means of transportation that replaces existing internal combustion engine vehicles, and the related market is rapidly expanding. Accordingly, characteristic lithium secondary batteries have become necessary, and in particular, lithium bis(fluorosulfonyl)imide salt is gaining commercial importance as it exhibits the required performance required for lithium secondary batteries for electric vehicles.

On the other hand, due to various limitations, it is still not easy to mass-produce lithium bis(fluorosulfonyl)imide salt inexpensively and economically.

Among these, the conventional method for producing lithium bis(fluorosulfonyl)imide, on which much research has been conducted, is explained as follows.

In U.S. Patent No. 8,926,930, bis(fluorosulfonyl)imide in the organic layer reacts with lithium hydroxide in the water layer to transfer lithium bis(fluorosulfonyl)imide to the organic layer and concentrate the organic layer to produce lithium bis(fluorosulfonyl)imide. Sulfonyl)imide is obtained, but in order to prevent the loss of lithium bis(fluorosulfonyl)imide to the water layer, an excessive amount of organic solvent must be used and excessive wastewater is generated, resulting in low productivity.

In addition, in International Publication No. WO2016/184176, lithium bis(fluorosulfonyl)imide is obtained by reacting bis(fluorosulfonyl)imide with lithium reagents such as lithium hydroxide monohydrate, lithium carbonate, and lithium bicarbonate. To remove moisture generated during production, thionyl chloride (SOCl ₂ ) is added to produce lithium bis(fluorosulfonyl)imide. However, the excess added thionyl chloride must be removed, and the content of impurities such as Cl ^- , SO ₄ ^2- , etc. in lithium bis(fluorosulfonyl)imide prepared under acidic reaction conditions is high. These impurities can cause corrosion problems when applied to lithium secondary batteries, which can be a fatal problem for stable operation in the long term.

In addition, in Domestic Publication Patent No. 10-2020-0005970, there is an example of using lithium-t-butoxide as a lithiation reagent to eliminate moisture generation. Lithium-t-butoxide is lithium oxide monohydrate, a commonly used lithiation reagent. , the reagent price is more than 3 times more expensive than lithium carbonate, and considering the molecular weight, it is 6 times the actual cost of use, so the price competitiveness of lithium bis(fluorosulfonyl)imide manufactured by this method is very poor.

As such, much research has been conducted on the production of bis(fluorosulfonyl)imide metal salts, including lithium bis(fluorosulfonyl)imide, but bis(fluorosulfonyl)imide can be produced more economically and is environmentally friendly. There is still a need for a method for producing imide metal salts.

US Patent No. 8,926,930 (registration date: 2015.01.06) International Publication Patent No. WO2016/184176 (Publication Date: 2017.11.29) Korean Patent Publication No. 10-2020-0005970 (Publication Date: 2020.01.17)

Accordingly, the purpose of the present invention is to provide a method for mass production of bis(fluorosulfonyl)imide metal salt that is environmentally friendly, economical, and efficient.

In addition, another object of the present invention is to provide a high-purity bis(fluorosulfonyl)imide metal salt prepared by the above production method.

While devising a method to more easily produce bis(fluorosulfonyl)imide metal salt with high purity and high yield through an eco-friendly and simple process, the present inventors used bis(fluorosulfonyl)imide or ammonium as a starting material. When preparing bis(fluorosulfonyl)imide metal salt by reacting bis(fluorosulfonyl)imide with a metallization reagent in powder form without a solvent, bis(fluorosulfonyl)imide metal salt is produced with high purity and high yield through concentration and drying (powderization). The present invention was completed by discovering that (fluorosulfonyl)imide metal salt can be easily mass-produced.

This manufacturing method does not use solvents during manufacturing, so there is no generation of organic waste, and since the metallization reagent is used in the form of metal powder rather than an aqueous solution, there is no wastewater generation. Accordingly, bis(fluorosulfonyl)imide metal salt can be produced in a very environmentally friendly manner, and a simple concentration and drying process is performed at high speed to continuously produce a large amount of bis(fluorosulfonyl)imide of high purity and high yield. Metal salts can be manufactured.

Accordingly, the present invention (i) reacts a bis(fluorosulfonyl)imide compound represented by Formula 1 below with a metallization reagent in powder form to produce a bis(fluorosulfonyl)imide metal salt represented by Formula 2 below. Preparing an aqueous solution of; and

(ii) preparing bis(fluorosulfonyl)imide metal salt powder represented by the following formula (2) by appropriately concentrating and drying the aqueous solution of the bis(fluorosulfonyl)imide metal salt, bis( A method for preparing fluorosulfonyl)imide metal salt is provided:

[Formula 1]

[Formula 2]

In Formula 1, A is H or NR ¹ R ² R ³ R ⁴ , R ¹ to R ⁴ may be the same or different, and is H or carbon containing a straight or branched chain hetero element of C1 to C20.

In Formula 2, M is lithium, sodium, or potassium.

In addition, the present invention provides a bis(fluorosulfonyl)imide metal salt having a purity of 99% or more prepared by the above production method.

The method for producing bis(fluorosulfonyl)imide metal salt according to the present invention involves reacting a bis(fluorosulfonyl)imide compound directly with a powdered metallization reagent without a solvent, thereby eliminating the generation of related waste, which is similar to the prior art. Unlike, bis(fluorosulfonyl)imide metal salt can be produced in an environmentally friendly manner.

In addition, this manufacturing method is very simple, but only a small amount of water (less than 10% by weight) generated during the reaction is quickly concentrated using appropriate concentration/drying equipment and the product is dried, producing high yield and high purity bis(fluorosulfonyl). Since the metal salt can be easily mass-produced and is very economical, the bis(fluorosulfonyl)imide metal salt prepared according to the present invention is widely used in secondary batteries or antistatic agents that require high output, such as electric vehicles (EV) and power tools. It can be applied.

Hereinafter, the present invention will be described in more detail.

First, looking at the conventional technology for making bis(fluorosulfonyl)imide metal salt, the reaction proceeds to the solution phase of bis(fluorosulfonyl)imide metal salt using various methods, the solvent is evaporated to make a concentrate, and the preparation is made. The solvent of 2 is added to induce crystallization of the bis(fluorosulfonyl)imide metal salt, and the resulting crystals are filtered out, recovered, and dried. In most cases, a solution phase of bis(fluorosulfonyl)imide metal salt is prepared by contacting an organic solution of bis(fluorosulfonyl)imide or an ammonium salt of bis(fluorosulfonyl)imide with an aqueous metallization reagent solution. .

In most cases, bis(fluorosulfonyl)imide metal salt has an unusually high affinity for solvents or water, so when commercialized using the above method, some of it dissolves in the solvent, inevitably lowering the yield and the purity of the crystallized product is also very high. It won't be high. This is because some pure bis(fluorosulfonyl)imide metal salt products are lost by dissolving in solvents or water. In addition, since the crystallization process inevitably requires the use of a second solvent that is insoluble in the product, the solvent mixture is generated as waste, and waste water from the aqueous solution of the metallization reagent is also generated.

As mentioned above, during this process, a small amount of water is not removed because it has a very high affinity for the bis(fluorosulfonyl)imide metal salt. On the other hand, due to the nature of the product as a secondary battery material, the product is in an anhydrous state of less than 100 ppm. Because it must be manufactured, it is not easy to remove a small amount of water by conventional methods, and the purity of the product may decrease due to the generation of impurities through processes such as raising the temperature for a long period of time during the removal process. In _addition , thionyl chloride ^, etc. are used to remove a small amount of water, but ^hydrochloric acid gas _and SO This is not desirable at all as it causes quality deterioration. In addition, concentrating water under reduced pressure using a general method requires a high temperature of 60℃ or higher, a high vacuum of 1.0 mmHg or lower, and a long period of time of 24 to 48 hours, so it is not economical at all and is not suitable for commercial production.

Meanwhile, the present inventor contacted bis(fluorosulfonyl)imide or an ammonium salt of bis(fluorosulfonyl)imide with a metallization reagent without a solvent to form bis( It was discovered that fluorosulfonyl)imide metal salt can be produced with high purity. As a representative example, when the metal is lithium and the solidification reagent is the most common lithium hydroxide monohydrate, lithium bis(fluorosulfonyl)imide can be produced in high yield and high purity. In this case, surprisingly, lithium bis(fluorosulfonyl)imide was maintained in a liquid state by the 2 equivalents of water generated. This is expected to be because lithium bis(fluorosulfonyl)imide has a very high affinity and solubility in water. After removing the insoluble matter through simple filtration, the purity, color, and impurity content were analyzed and all of them met the standards. The key was whether about 10% by weight of water could be concentrated and dried to the product standard of 100 ppm or less, preferably 50 ppm or less, in a short period of time without deteriorating product purity.

Accordingly, while devising various methods, the present inventor predicted that when the solution phase was made into a thin film, the volatility would be significantly superior to that of the conventional method, and that this phenomenon could be attributed to the above-mentioned lithium bis containing about 10% by weight of water. It was confirmed whether it could be applied to an aqueous solution of (fluorosulfonyl)imide. Surprisingly, when applying an agitated thin film dryer with an internal structure capable of creating a thin film that can be stirred, water can be easily concentrated in a very short time and solidified to produce high purity lithium bis(fluorosulphate) with a moisture content of 100 ppm or less. It was confirmed that ponyl)imide products could be manufactured without deteriorating purity. When analyzing the purity, color, and impurity content of the lithium bis(fluorosulfonyl)imide product manufactured in this way, it was found that all of them satisfied the specifications.

Through this, it was confirmed that bis(fluorosulfonyl)imide metal salt can be easily industrially synthesized in large quantities. In the past, the metallization reagent was used in the form of an aqueous solution in the metallization step, which inevitably resulted in the use of excessive water, which inevitably resulted in the generation of waste water. However, in the present invention, by using a powder-like metallization reagent, there is no use of water and no waste water is generated. , no solvent was used during the reaction, so no organic waste was generated.

In addition, in the past, bis(fluorosulfonyl)imide metal salt was difficult to concentrate in an organic solvent, a product was produced from the concentrate through recrystallization, and the product was dried to produce a product, which went through three separate stages of concentration, production, and drying. Although economics and workability are reduced due to time, reduction in purity and yield, waste generation, and increase in process cost, the inventor's development process performs this in one go and is far superior to existing processes in terms of purity, yield, environment, and economics.

In addition, since the solid concentration of bis(fluorosulfonyl)imide metal salt is 80 to 96% by weight, the amount of water to be removed through concentration and drying is only 20 to 4% by weight, so productivity is very high relative to the dryer capacity, especially for mass production. The present invention was completed by discovering that bis(fluorosulfonyl)imide metal salt can be produced in an advantageous and economical manner.

Hereinafter, the present invention will be described in more detail as an embodiment as follows.

The present invention (i) reacts a bis(fluorosulfonyl)imide compound represented by the following formula 1 with a metallization reagent in powder form to produce an aqueous solution of the bis(fluorosulfonyl)imide metal salt represented by the formula 2 below. manufacturing a; and

(ii) preparing bis(fluorosulfonyl)imide metal salt powder represented by the following formula (2) by appropriately concentrating and drying the aqueous solution of the bis(fluorosulfonyl)imide metal salt, bis( A method for preparing fluorosulfonyl)imide metal salt is provided:

[Formula 1]

[Formula 2]

In Formula 1, A is H or NR ¹ R ² R ³ R ⁴ , R ¹ to R ⁴ may be the same or different, and is H or carbon containing a straight or branched chain hetero element of C1 to C20.

In Formula 2, M may be lithium, sodium, or potassium.

In the present invention, the bis(fluorosulfonyl)imide metal salt represented by Chemical Formula 2 can be prepared as shown in Scheme 1 below:

[Scheme 1]

First, step (i) is a step of preparing an aqueous solution of bis(fluorosulfonyl)imide metal salt by reacting the bis(fluorosulfonyl)imide compound with a metallization reagent in powder form.

In the present invention, it is preferable to use metal salt powder as a metallizing reagent for metallization. Conventionally, metal salt powder was prepared in the form of an aqueous solution before use, but the use of this aqueous solution had a limitation in that the concentration of the reaction solution had to be diluted to prevent loss of the bis(fluorosulfonyl)imide metal salt into the water layer. However, the manufacturing method of the present invention uses metal salt powder as is to proceed with the reaction, so it is possible to carry out the reaction at high concentration, which is advantageous for mass production, and is very environmentally friendly as it does not generate unnecessary waste water. This is different from conventional manufacturing methods.

In detail, the metalizing reagent may be one or more selected from the group consisting of hydroxide salts, carbonate salts, and bicarbonate salts of metals selected from lithium, sodium, or potassium, but is not limited thereto. At this time, the metallization reagent may be used in an equivalent ratio of 1.0 to 1.1 compared to bis(fluorosulfonyl)imide, but is not limited thereto.

Depending on the metallization reagent used in step (i), 1 to 2 equivalents of water are generated, which is water generated as a result of the reaction between bis(fluorosulfonyl)imide and the metallization reagent. For example, when the metallization reagent is sodium hydroxide, sodium bis(fluorosulfonyl)imide is synthesized, as can be seen in Scheme 1 above, and 1 equivalent of water is also generated. When the metallization reagent is lithium hydroxide monohydrate, 1 equivalent of water is synthesized through the reaction between bis(fluorosulfonyl)imide and lithium hydroxide, and 1 equivalent of water is also added. This occurs and 1 equivalent of water is generated from lithium hydroxide monohydrate. Therefore, in this case, 2 equivalents of water are generated.

In step (i), the reaction temperature is -30°C to 100°C and the reaction time is preferably 0.5 to 4 hours. If the reaction temperature is less than -30°C, the reaction rate slows down, and if it exceeds 100°C, the impurity content increases. .

In addition, a step of filtering and removing insoluble substances from the product produced after step (i) above may be performed, but such purification or filtration process is not necessarily required.

Next, step (ii) is a step of rapidly concentrating and drying the water generated from the product containing a small amount of water in (i) using suitable drying equipment to produce bis(fluorosulfonyl)imide metal salt. am.

The above concentration can use general reduced pressure concentration, but the concentration requires a high temperature of 60°C or higher, a high vacuum of 1.0 mmHg or less, and a long period of time of 24 to 48 hours, making it not economical at all and not suitable for commercial production. Even in this case, it is almost impossible to achieve a moisture content of 100 ppm, preferably 50 ppm or less, which is sufficient for commercialization. Additionally, during this process, some products decompose, causing problems such as lowering product purity and increasing acidity and anion impurity content. Additionally, the process time is also very long, 1 to 2 working days, so it is not suitable for mass production. Equipment investment costs are also excessive, making it difficult to manufacture competitive products.

Therefore, in the present invention, concentration and drying are performed using an agitated thin film dryer that is capable of stirring, heating, and has dense blades with guaranteed hardness installed inside, enabling the creation of a thin film at the liquid product stage. It can be performed using . The dryer can be either horizontal or vertical, and the operating conditions are that it is performed at a temperature of 100℃ or less, preferably 0℃ to 60℃, and the stirring speed is 30 to 6000 rpm. , At this time, it is desirable to carry out the procedure in a vacuum state with an atmospheric pressure of 0.001 to 100 mmHg. Additionally, concentration and drying are preferably performed by passing dried nitrogen.

When processing the product in step (i) in the above process, the contact time is only 5 to 10 minutes, and using commercial equipment, the product can be concentrated and dried at a rate of several tons/hour, which is As a result of measuring the moisture of the product, it was sufficiently excellent at less than 50 ppm, and product purity, acidity, and anion impurity content were all satisfied within the specifications.

And, after step (ii), a step of recrystallizing the bis(fluorosulfonyl)imide metal salt may be further included. Specifically, after step (ii), the product obtained is dissolved in a solvent selected from the group consisting of alkanes, alcohols, ketones, ethers, esters, and carbonates, and then the insoluble matter is removed, concentrated, and dried. It can be further purified.

In addition, the present invention provides a bis(fluorosulfonyl)imide metal salt having a high purity of 99% or more, prepared by the above production method. The bis(fluorosulfonyl)imide metal salt prepared according to the present invention has high purity and extremely low impurities, and when used as a metal salt in an electrolyte solution for a secondary battery, it can improve the electrochemical properties, output, and lifespan characteristics of the secondary battery.

Hereinafter, the new method for producing bis(fluorosulfonyl)imide metal salt according to the present invention will be described in more detail through the following examples. However, the present invention is not limited to these examples.

Example 1. Preparation of aqueous solution of lithium bis(fluorosulfonyl)imide salt using bis(fluorosulfonyl)imide and lithium hydroxide monohydrate powder

Slowly add 42.0 g of lithium hydroxide monohydrate to 181.1 g of bis(fluorosulfonyl)imide in a 500 mL container equipped with a stirring device, condenser, and thermometer at 0°C, and stir the mixture when the reactant becomes liquid. It was reacted until.

Afterwards, the insoluble matter was filtered through filter paper, and 219.0 g of an aqueous solution of lithium bis(fluorosulfonyl)imide salt, a colorless and transparent liquid, was obtained. (Yield: 98%, purity: 99.3%, acidity: 10 ppm, Cl ^- : 2.3 ppm, SO ₄ ^2- : 3.1 ppm).

Example 2. Preparation of aqueous solution of sodium bis(fluorosulfonyl)imide salt using bis(fluorosulfonyl)imide and sodium hydroxide powder

212.3 g of an aqueous solution of sodium bis(fluorosulfonyl)imide salt was obtained in the same manner as in Example 1, except that 40.0 g of sodium hydroxide powder was used instead of 42.0 g of lithium hydroxide monohydrate (yield: 96%). , purity: 99.2%, acidity: 13 ppm, Cl ^- : 3.1 ppm, SO ₄ ^2- : 4.5 ppm).

Example 3. Preparation of aqueous solution of potassium bis(fluorosulfonyl)imide salt using bis(fluorosulfonyl)imide and potassium hydroxide powder

234.8 g of an aqueous solution of potassium bis(fluorosulfonyl)imide salt was obtained by preparing in the same manner as Example 1, except that 66.0 g of potassium hydroxide was used instead of 42.0 g of lithium hydroxide monohydrate (yield: 95%, Purity: 99.2%, acidity: 8 ppm, Cl ^- : 2.0 ppm, SO ₄ ^2- : 2.9 ppm).

Example 4. Preparation of aqueous solution of lithium bis(fluorosulfonyl)imide salt using bis(fluorosulfonyl)imide and lithium carbonate powder

184.3 g of an aqueous solution of lithium bis(fluorosulfonyl)imide salt was obtained by preparing in the same manner as in Example 1, except that 37.1 g of lithium carbonate was used instead of 42.0 g of lithium hydroxide monohydrate (yield: 94%, Purity: 99.0%, acidity: 30 ppm, Cl ^- : 4.4 ppm, SO ₄ ^2- : 3.0 ppm).

Example 5. Preparation of aqueous solution of lithium bis(fluorosulfonyl)imide salt using bis(fluorosulfonyl)imide and lithium bicarbonate powder

182.5 g of an aqueous solution of lithium bis(fluorosulfonyl)imide salt was obtained by preparing in the same manner as Example 1, except that 68.0 g of lithium bicarbonate was used instead of 42.0 g of lithium hydroxide monohydrate (yield: 89%). , purity: 98.3%, acidity: 47 ppm, Cl ^- : 4.9 ppm, SO ₄ ^2- : 5.2 ppm).

Example 6. Preparation of aqueous solution of lithium bis(fluorosulfonyl)imide salt using ammonium bis(fluorosulfonyl)imide and lithium hydroxide monohydrate powder

Slowly add 42.0 g of lithium hydroxide monohydrate to 198.1 g of ammonium bis(fluorosulfonyl)imide in a 500 mL container equipped with a stirring device, condenser, and thermometer at 0°C, and stir the mixture under vacuum to 20°C. The temperature was gradually raised and the reaction was allowed to react until the reactant became liquid.

Afterwards, the insoluble matter was filtered through filter paper, and 221.2 g of an aqueous solution of lithium bis(fluorosulfonyl)imide salt, a colorless and transparent liquid, was obtained. (Yield: 99%, Purity: 99.4%, Acidity: 4 ppm, Cl ^- : 2.0 ppm, SO ₄ ^2- : 2.9 ppm).

Example 7. Preparation of aqueous solution of sodium bis(fluorosulfonyl)imide salt using ammonium bis(fluorosulfonyl)imide and sodium hydroxide powder

140.6 g of sodium bis(fluorosulfonyl)imide was obtained in the same manner as in Example 6, except that 40.0 g of sodium hydroxide powder was used instead of 42.0 g of lithium hydroxide monohydrate (yield: 98%, purity: 99.1) %, acidity: 10 ppm, Cl ^- : 2.3 ppm, SO ₄ ^2- : 3.1 ppm).

Example 8. Preparation of aqueous solution of calcium bis(fluorosulfonyl)imide salt using ammonium bis(fluorosulfonyl)imide and potassium hydroxide powder

134.9 g of sodium bis(fluorosulfonyl)imide was obtained in the same manner as in Example 6, except that 66.0 g of potassium hydroxide was used instead of 42.0 g of lithium hydroxide monohydrate (yield: 94%, purity: 99.4%) , acidity: 12 ppm, Cl ^- : 2.5 ppm, SO ₄ ^2- : 3.7 ppm).

Example 9. Concentration and drying of aqueous lithium bis(fluorosulfonyl)imide solution

Under a nitrogen atmosphere, lithium bis(fluorosulfonyl) obtained in Example 1 was obtained using a vertical stirrer-thin film dryer equipped with a stirrer device, a vacuum device, an internal blade capable of forming a thin film, a heating jacket, and an internal grinding device. 219.0 g of an aqueous imide solution (purity: 99.3%; solid content: 90.3% by weight) was concentrated and dried. At this time, the stirring speed was 600 rpm, the supplied heat temperature was 40 ℃, the vacuum degree was 0.1 mmHg, and the contact time was 10 minutes, and 215.3 g of lithium bis(fluorosulfonyl)imide salt compound dried into white powder was added. Obtained (yield: 99%, purity: 99.2%, moisture: 37 ppm, acidity: 9 ppm, Cl ^- : 2.3 ppm, SO ₄ ^2- : 3.3 ppm).

As described above, although the present invention has been described in terms of limited embodiments, the present invention is not limited thereto, and the technical idea of the present invention and the claims described below will be understood by those skilled in the art. Of course, various modifications and variations are possible within the scope of equality.

Claims (12)

(i) Preparing an aqueous solution of bis(fluorosulfonyl)imide metal salt represented by Formula 2 by reacting the bis(fluorosulfonyl)imide compound represented by Formula 1 below with a metallization reagent in powder form. step; and
(ii) Concentrating and drying the aqueous solution of the bis(fluorosulfonyl)imide metal salt using a stirred thin film dryer capable of forming a thin film to obtain bis ( Comprising the step of preparing fluorosulfonyl)imide metal salt powder,
To have a yield of 90% or more through steps (i) and (ii),
Method for preparing bis(fluorosulfonyl)imide metal salt:
[Formula 1]

[Formula 2]

In Formula 1, A is H or NR ¹ R ² R ³ R ⁴ , R ¹ to R ⁴ may be the same or different, and is H or carbon containing a straight or branched chain hetero element of C1 to C20,
In Formula 2, M is lithium, sodium, or potassium.
According to claim 1,
A method for producing a bis(fluorosulfonyl)imide metal salt, wherein the metalizing reagent is one selected from the group consisting of hydroxide salts, carbonate salts, and bicarbonate salts of a metal selected from lithium, sodium, or potassium. .
According to claim 1,
A method for producing a bis(fluorosulfonyl)imide metal salt, characterized in that the metalizing reagent is used in an equivalent ratio of 1.0 to 1.1 compared to the bis(fluorosulfonyl)imide compound.
delete delete According to claim 1,
A method for producing bis(fluorosulfonyl)imide metal salt, characterized in that the concentration and drying are performed by passing dried nitrogen.
According to claim 1,
A method for producing bis(fluorosulfonyl)imide metal salt, characterized in that the concentration and drying are performed at a temperature of 0 ℃ to 100 ℃.
According to claim 1,
A method for producing bis(fluorosulfonyl)imide metal salt, characterized in that the concentration and drying are performed under a vacuum of 0.001 to 100 mmHg.
According to claim 1,
A method for producing bis(fluorosulfonyl)imide metal salt, characterized in that the stirring speed during the concentration and drying is performed at 30 to 6000 rpm.
delete delete delete