KR102101982B1 - A method for synthesis of methyl disulfonate compounds - Google Patents

Abstract

본 발명은 합성 방법이 간단하고, 높은 수율과 최종 제품의 높은 순도, 낮은 수분 함량, 낮은 산가를 가지며, 전지 전해액에 사용할 시 전해액 성능을 대폭 상승시킬 수 있다.Method for synthesizing methanedisulfonate compound, technical area of battery electrolyte additive, obtained by reacting alkane disulfonic acid and formaldehyde compound in the presence of a dehydrating agent. The dehydrating agent is a neutral dehydrating agent, and the alkanedisulfonic acid is a sulfonic acid compound of formula I structure, so that the molecular weight of the formaldehyde compound and the alkanedisulfonic acid is adjusted to ≥1. Among them, R ₁ and R ₂ Is a C _{1 -4} al kalgi to replace an independent hydrogen atom or a hydrogen atom, a halogen atom. N is an integer from 1 to 4, and when n is an integer from 2 to 4, n R ₁ And n R ₂ Can be the same or different.

The present invention is a simple synthesis method, has high yield, high purity of the final product, low moisture content, low acid value, and can significantly increase electrolyte performance when used in a battery electrolyte.

Description

A method for synthesis of methyl disulfonate compounds

The present invention is a technical area of a battery electrolyte additive, and includes a kind of methanedisulfonate compound, which is a battery electrolyte additive, and includes a specific method for synthesizing a related methanedisulfonate compound. The present invention is a simple synthesis method, has high yield, high purity of the final product, low moisture content, low acid value, and can significantly increase electrolyte performance when used in a battery electrolyte.

The methanedisulfonate compound is also used as a therapeutic agent for animal leukemia, and the sulfonic acid group included in the structure can react with atomic groups such as alcohol, phenol, and sulfur alcohol under certain conditions, and its unique structure plays an important role in the synthesis of heterocyclic drugs. Is doing. With the development of new energy technology, the application technology of methanedisulfonate compound in lithium battery electrolyte additives is also gradually being developed. When the methanedisulfonate compound is used in the lithium battery electrolyte additive, the performance of the battery can be significantly improved, and the number of charges and the circulation characteristics of the battery can be increased. However, the conventional method for producing a methane disulfonate compound has a high moisture content and production cost of the product, and when used in a battery, it causes phenomena such as decomposition, expansion, and swelling of the electrolyte, and in serious cases, instead of improving battery performance, The case is also unusual. Therefore, the water content and acid value of additives must be strictly defined.

There are several existing methods for preparing methanedisulfonate compounds.

(1) Sulfuryl chloride and silver carbonate are reacted to obtain silver sulfonate, and sulfonate methylene iodide is reacted. R is a hydrogen atom or a methyl group:

In the above method, silver carbonate and methylene iodide used as raw materials are not only expensive, but also have a slow reaction rate and low yield.

(2) React with alkylsulfonic acid and methyl acetate. R 'and R "are independent hydrogen atoms or alkyl groups.

However, methyl acetate used as a raw material in the above method is not only very expensive, but also difficult to obtain, and other raw materials, alkylsulfonic acid, are expensive and difficult to utilize in the industry.

(3) When using a dehydrating agent, react with a formaldehyde compound and any one of the alkylsulfonic acid alkali metal salts (see Formula 1) and the alkylsulfonic acid alkaline earth metal salts (see Formula 2).

Although the above method slightly reduced the production cost, the two raw materials used, the alkali metal sulfonate metal salt (refer to formula 1) and the alkali earth metal salt sulfonate (refer to formula 2), are still expensive and difficult to obtain.

(4) When a dehydrating agent is used, it is prepared by reacting a formaldehyde compound with an alkane disulfonic acid.

Although the above method slightly reduced the production cost, there is a disadvantage that the yield is only about 50%. In addition, the product has a high water content and acid value, which affects performance when used in batteries, thus reducing industrial value.

Chinese patent application number 200780014629.X

The present invention provides a method for synthesizing a methanedisulfonate compound to solve the above problems. The stable synthesis process significantly improved yield and product quality.

The structural formula of the methanedisulfonate compound described in the present invention is as shown in Formula II below: R ₁ and R ₂ are independent hydrogen atoms or C _1-4 alkyl groups in which hydrogen atoms can be substituted with halogen atoms. n is an integer from 1 to 4, and when n is an integer from 2 to 4, n R ₁ and n R ₂ may be the same or different;

The technical proposal to achieve this goal is as follows.

Synthesis method of related methanedisulfonate compound, synthesized by reacting alkanedisulfonic acid and formaldehyde compound in the presence of a dehydrating agent. The dehydrating agent is a neutral dehydrating agent, and the alkanedisulfonic acid is a sulfonic acid compound of formula I structure, so that the molecular weight of the formaldehyde compound and the alkanedisulfonic acid is adjusted to ≥1. Among them, R ₁ and R ₂ are independent hydrogen atoms or hydrogen atoms are C _1-4 alkyl groups which may be substituted with halogen atoms. n is an integer from 1 to 4, and when n is an integer from 2 to 4, n R ₁ and n R ₂ may be the same or different.

The molecular ratio of the formaldehyde compound and the alkane disulfonic acid is (1-1.3): 1. A small amount of formaldehyde compounds should be used, otherwise the moisture content of the final product rises. For this reason, the molecular ratio of alkane disulfonic acid is designated as (1-1.3): 1.

The reaction temperature is 100 ° C or less, and the reaction time is 1-2h. The reaction temperature is set to 100 ° C. or less to prevent moisture from evaporating and then cooling the methanedisulfonate compound due to cooling to contact with it to contain moisture in the crystals to increase the moisture content.

During the reaction, a three-stage temperature control method is used. The temperature of the first stage is the lowest, the temperature of the third stage is the middle, and the temperature of the second stage is the highest. Specifically, the reaction was performed for 15-20 minutes at a temperature of 20-30 ° C, the reaction was performed for 30-50 minutes at 50-90 ° C, and the reaction was performed for 20-25 minutes at 30-50 ° C. However, the temperature in the third stage must be higher than the first stage and lower than the second stage. First of all, the low-temperature reaction at 20-30 ° C causes a violent reaction at a sudden high temperature to prevent the mixing of by-products or moisture, and buffers to ensure stability of the reaction process. The high-temperature reaction at 50-90 ° C promotes the progress of the reaction to accelerate the reaction rate. The low temperature of the last 30-50 ℃ is a buffering process of the reaction, to maintain a stable and continuous reaction process. At the same time, the last step also has the effect of shortening the cooling time after the completion of the reaction, and also prevents the crystals from containing moisture due to a large temperature difference. The three-stage temperature control system can significantly reduce the reaction time.

The molecular ratio between the dehydrating agent and the alkane disulfonic acid is (1-1.3): 1.

The neutral dehydrating agent is one of anhydrous magnesium sulfate, anhydrous sodium sulfate, anhydrous calcium sulfate, molecular sieve, silica gel, or a combination thereof.

The formaldehyde compound is one of paraformaldehyde, anhydrous formaldehyde, and trioxane, or a combination thereof.

As a specific method for separating a mixture containing a methane disulfonate compound: extraction is performed by adding an extraction solvent. The extract was decolorized and subjected to suction filtration, concentration, crystallization, and drying to obtain a methanedisulfonate compound.

As the extraction solvent, any one of methylene chloride, chloroform, carbon tetrachloride, ethyl acetate, methyl acetate, and isopropyl acetate or a mixture thereof is used, and the mass ratio of the extraction solvent to the alkanedisulfonic acid is (4-10): 1. The capacity of the extraction solvent can be regarded as the key to the extraction effect. When the capacity is insufficient, the yield is lowered because it cannot be completely extracted, and if the capacity is excessive, inconvenience of removing the extraction solvent occurs and it takes time. At the same time, partial hydrolysis occurs, which affects the yield and quality of the product.

When selecting the temperature at the time of crystallization, first store for 10-15 minutes at -10 to 15 ° C, then cool to -30 to -40 ° C at a rate of 1-2 ° C / min to complete the crystal. The determination method and conditions used in the present invention is to prevent moisture from increasing the water content and thus affecting the properties and performance of the product.

The production method of the methane disulfonate compound in the present invention is excellent in low cost and economic efficiency, and ensures a stable reaction. Alcandisulfonic acid exists in two forms, solid and liquid, so that it can react directly with reactants, and can react in solution. There is an advantage that the operation of the process is easy. In addition, there is an advantage that the reaction yield of the alkanesulfonic acid and formaldehyde compounds reaches 75% or more. It is clear that it has achieved great results compared to the 25% yield of the prior art. At the same time, the acid value and water content also drastically decreased, and this effect markedly reduced the expansion and swelling of the battery.

The present invention specifically emphasized the use of a neutral dehydrating agent, which is one reason for promoting the reaction and improving the conversion rate. On the one hand, according to our research results, when using an acidic dehydrating agent such as phosphorus pentoxide, it is combined with moisture to create a fine acid environment and synthesized methane. This is because the disulfonate compound can cause a hydrolysis phenomenon and lower the final yield. The reason for this is that the prior art is the main reason that the yield of the synthesis of the formaldehyde compound and the alkane disulfonic acid as a raw material is only about 50% (for example, there is a patent specification of application number 200780014629.X). This micro-environment can easily be overlooked and seems like a small problem, but it can have a big impact. No research has been conducted at this time. The prior art has not yet found a major cause, and at the same time, when an acidic dehydrating agent is used, the acid value of the synthesized methanedisulfonate compound increases, which affects the performance in the battery. When using a basic dehydrating agent, it not only suppresses the progress of the positive reaction, but also causes side reactions of the sulfonic acid compound and the basic substance, which greatly affects the yield and quality of the product.

In the present invention, it is emphasized that the molecular ratio of the formaldehyde compound and the alkynesisulfonic acid should be adjusted to ≥ 1, but the formaldehyde substances must be relatively large. The purpose is not to react alkanesulfonic acid, but to create a stable environment for the presence of a methanedisulfonate compound to prevent the problem of lowering yield and improving acid value due to hydrolysis of the methanedisulfonate compound. When the amount of alkane disulfonic acid is relatively large, it is difficult to obtain the above effects. Alkanedisulfonic acid excess causes hydrolysis of the partial methanedisulfonate compound, destroying the stable environment of the methanedisulfonate compound. In addition, the excess of alkenesulfonic acid leads to high acid values. This is also the reason for the low yield and high acid value of the prior art.

The present invention will be described through specific examples below.

1. Specific Examples

Example 1

1760 g (10 mol) of methanedisulfonic acid and 1204 g (10 mol) of anhydrous magnesium sulfate were added to the reactor equipped with a stirrer, cooler and thermometer, and 359 g (11 mol) of 92% paraformaldehyde was added under conditions of room temperature and stirring. do. After the addition, the mixture was continuously stirred and reacted for 15 min under 20-30 ° C., reacted for 30 min under 50-90 ° C., reacted for 20 min under 35-45 ° C., cooled to room temperature, and 7050 g of methylene chloride was added to proceed with extraction. . All extracts are decolorized by adding activated carbon, filtered by suction, concentrated, and insulated at -10 ° C for 10min. Thereafter, the temperature is lowered to -30 ° C at a rate of 1 ° C / min to finish the crystal. Filtration and drying under reduced pressure yielded 1447.6 g of white crystals of methanedisulfonate. Its yield is 77%. Nuclear magnetic walking 1H-NMR (400MHz, CD3CN) δ (ppm): 5.33 (s, 2H), 6.00 (s, 2H). As a result of the verification, the moisture content was 10 ppm and the acid value was 15 ppm.

Example 2

1900 g (10 mol) 1,2-ethanesulfonic acid and 1846 g (13 mol) anhydrous sodium sulfate were added to the reactor equipped with a stirrer, cooler and thermometer, and 423 g (13 mol) 92% paraform under conditions of room temperature and stirring. Add aldehyde. After the addition, the mixture was continuously stirred, reacted for 20 min under 23-25 ° C, reacted for 40 min under 60-80 ° C, reacted for 25 min under 30-40 ° C, cooled to room temperature, and 9500 g of chloroform (carbon tetrachloride of the same mass, ethyl acetate) , Can be changed to one or several of methyl acetate and isopropyl acetate) to proceed extraction. All extracts were decolorized by adding activated carbon, filtered by suction and concentrated, and then kept warm at -15 ° C for 15min. Thereafter, the crystal was finished by lowering it to -40 ° C at a rate of 2 ° C / min. Filtration and drying under reduced pressure gave 1585.7 g of white crystals 1,2-ethanedulfonate. Its yield is 78.5%. Nuclear magnetic walking 1H-NMR (400MHz, CD3CN) δ (ppm): 3.83 (s, 4H), 5.63 (s, 2H). As a result of the verification, the moisture content was 13 ppm and the acid value was 15 ppm.

Example 3

2,600 g (10 mol) of 1,1-dipropylmethane disulfonic acid and 1440 g (12 mol) of anhydrous magnesium sulfate (sodium sulfate anhydrous in the same amount of substance, anhydrous calcium sulfate, molecular sieve, in a reaction device equipped with a stirrer, cooler, and thermometer), Silica gel can be changed to one or several types) and 326 g (10 mol) of 92% paraformaldehyde (can be changed to anhydrous formaldehyde or trioxane in the same amount) under the conditions of room temperature and stirring. . After the addition, the mixture was continuously stirred and reacted for 18 min under 25-28 ° C., reacted for 50 min under 70-90 ° C., reacted for 20 min under 40-50 ° C., cooled to room temperature, and 26,000 g carbon tetrachloride was added to proceed with extraction. All extracts were decolorized by adding activated carbon, filtered by suction and concentrated, and insulated at -13 ° C for 13 min. Thereafter, the crystal was terminated by lowering it to -35 ° C at a rate of 1.5 ° C / min, and 2110.7g of crystalline 1,1-dipropylmethanedisulfonate was obtained through filtration, drying at 40 ° C and 10 mmHg for 3 h. Its yield is 77.6%. Nuclear magnetic walking 1H-NMR (400MHz, CD3CN) δ (ppm): 5.72 （s, 2H）, 2.33 （s, 4H）, 1.33 （s, 4H） 0.90 （s, 6H）. As a result of the verification, the water content was 15 ppm and the acid value was 17 ppm.

Comparative Example 1

Compared with Example 1, other conditions are the same except that an acidic catalyst such as phosphorus pentoxide is used. 996.4 g of product was obtained, yield was 53%, water content was 58 ppm, and the acid value was 70 ppm.

Comparative Example 2

Compared with Example 1, other conditions were the same except that 1760 g (10 mol) dimethyl sulfone and 261 g (8 mol) 92% of paraformaldehyde were added. 821.2 g of product was obtained, the yield was 54.6%, the moisture content was 60 ppm, and the acid value was 80 ppm.

Comparative Example 3

8.8 g (0.05 mol) dimethylsulfonic acid and 7.1 g (0.05 mol) phosphorus pentoxide are added to a 200 ml four-neck flask equipped with a stirrer, cooler and thermometer. Under the conditions of room temperature and stirring, 1.6 g (0.05 mol) of 92% paraformaldehyde was added to the mixture. After addition, the mixture was heated to 120 ° C. and stirred for 1 h. The mixture is then cooled to room temperature and 100 g of methylene chloride is added. After stirring for 1 h, the insoluble material was filtered and concentrated to filter the crystals, and the crystals were dried for 6 h under conditions of 10 mmHg at 40 ° C. 4.7 g of methane disulfonate light brown crystals were obtained, yield was 50%, moisture content was 65 ppm, and acid value was 86 ppm.

Comparative Example 4

In a 200 ml four-necked flask equipped with a stirrer, cooler and thermometer, add 9.5 g (0.05 mol) of 1,2-ethanedisulphonic acid and 8.5 g (0.06 mol) of phosphorus pentoxide. Under the conditions of room temperature and stirring, 2.0 g (0.06 mol) 92% of paraformaldehyde is added to the mixture. After addition, the mixture was heated to 120 ° C. and stirred for 1 h. The mixture is then cooled to room temperature and 100 g of methylene chloride is added. After stirring for 1 h, the insoluble material was filtered and concentrated to filter the crystals, and the crystals were dried for 6 h under conditions of 10 mmHg at 40 ° C. Obtained 7.0 g of 1,2-ethaned disulfonate light brown crystals, the yield was 69.2%, the water content was 73 ppm, and the acid value was 90 ppm.

2. Application experiment

The development and application of battery additives are all aimed at improving the performance of the battery. Among them, the acid value and water content of the additive affect battery performance and also the life of the electrolyte. The high acid value and water content cause acid hydrolysis, which causes problems such as expansion and affects the high temperature stability of the battery. The methane disulfonate compound prepared by the above method is used as an additive and added to the same electrolytic solution in the same amount of addition to test the battery performance and to perform comparison and verification.

The product obtained by the above-mentioned "1. Specific Example" is added to the basic electrolyte solution. The addition amount is 1% of the mass of the basic electrolyte solution, and the electrolyte of the basic electrolyte battery is: DC / EMC = 1/3, LiPF ₆ : 1.1MFEC, PST, and the distribution of the positive and negative electrode current collectors is aluminum foil and copper foil, respectively. It is a soft packaging battery made of a magnetic diaphragm. After the electrolyte is added, the glove box is assembled with a soft packaging battery, and then left for 8 hours, and an experiment is conducted to test application performance. The results are as follows.

1, charging and discharging from 3.0V to 4.5V at 1 / 10C each at a constant temperature of 25 ° C to activate the battery. Cyclic charge discharge proceeds to 1C under the condition of 45 ° C immediately. Table 1 shows the results of the circulation experiment.

Room temperature circulation test project 300 times 45 ℃ Circulation capacity retention rate% 400 times 45 ℃ Circulation capacity retention rate% 500 times 45 ℃ Circulation capacity retention rate% 600 times 45 ℃ Circulation capacity retention rate% Example 1 93.5 89.4 86.8 83.6 Example 2 92.8 89.2 86.6 82.7 Example 3 92.4 88.9 86.3 82.5 Comparative Example 1 89.6 84.7 76.4 70.2 Comparative Example 2 88.3 80.2 74.3 66.5 Comparative Example 3 85.6 76.5 70.2 61.4 Comparative Example 4 85.3 75.8 70.1 58.3

2, Battery discharge retention rate under different magnification: The battery is subjected to constant current discharge at 0.5C to 3.0V, and after 5 minutes of standing, it is charged at 0.5C to 4.5V. After the current reaches 0.05C, it is left for 5 min, and then discharged up to a voltage of 3.0 V with a constant current of 0.2C, 1C, 1.5C, and 2C. The discharge capacity under 0.2C, 1C, 1.5C, and 2C conditions is recorded as D1, and the discharge capacity under 0.2C is recorded as D0. The discharge capacity of 0.2C or less is calculated by the formula of the discharge capacity retention rate of the battery = [(D1-D0) / D0] x 100%, and the discharge capacity retention rate of the batteries under different magnifications (measured 15 cells to give an average value) ). The discharge capacity retention rate of each battery under conditions of 25 ° C and a different magnification is shown in Table 2 below.

Item
Discharge capacity retention rate under different magnification% 0.2C 1C 1.5C 2C Example 1 100 95.1 92.4 89.2 Example 2 100 94.6 92.1 88.8 Example 3 100 94.2 91.6 88.3 Comparative Example 1 100 92.7 90.2 78.6 Comparative Example 2 100 91.8 88.3 72.3 Comparative Example 3 100 89.6 82.1 68.9 Comparative Example 4 100 89.2 81.6 67.6

3, battery high temperature storage performance evaluation: storage performance test of 60 ℃ / 30D and 85 ℃ / 7D Table 3 shows that the battery is left at 60 ℃ for 30 days and left at 85 ℃ for 7 days after standard charging and discharging. , It is the result of measuring the capacity retention rate and the capacity recovery rate of the battery.

Item
60 ℃ / 30D 85 ℃ / 7D Capacity retention rate% Capacity recovery rate% Capacity retention rate% Capacity recovery rate% Example 1 92.1 95.4 90.2 92.5 Example 2 91.6 93.5 88.6 90.4 Example 3 91.3 93.2 87.7 89.3 Comparative Example 1 78.1 80.2 75.8 74.5 Comparative Example 2 74.5 77.6 71.4 73.6 Comparative Example 3 63.2 65.4 60.3 62.5 Comparative Example 4 61.4 63.8 58.6 60.2

4, battery cold storage performance evaluation: Table 4 below shows the results of leaving the battery in a low-temperature box at -30 ° C or -40 ° C for 240 min and measuring the capacity retention rate of the battery.

Item
-30 ℃ -40 ℃ Capacity retention rate% Capacity retention rate% Example 1 90.2 84.5 Example 2 88.6 81.2 Example 3 87.4 80.3 Comparative Example 1 77.5 71.3 Comparative Example 2 73.7 69.6 Comparative Example 3 62.7 58.9 Comparative Example 4 60.3 56.4

Claims (10)

As a method for synthesizing a methanedisulfonate compound,
After administration of the dehydrating agent, the mixture containing the methanedisulfonate compound is separated by reacting the alkane disulfonic acid and the formaldehyde compound,
The dehydrating agent uses a neutral dehydrating agent, and the alkanedisulfonic acid uses a sulfonic acid compound of the formula I structure below,
The molecular ratio of the formaldehyde compound to the alkane disulfonic acid is 1 or more,
Among them, R ₁ and R ₂ are independently a hydrogen atom or a C _1-4 alkyl group in which the hydrogen atom may be substituted with a halogen atom, n is an integer up to 1-4, and n is an integer up to 2-4, n R ₁ and n R ₂ may be the same or different,
In the reaction, a three-stage temperature control method is used, the temperature of the first stage is the lowest, the temperature of the third stage is the middle, and the temperature of the second stage is the highest, specifically, at a temperature of 20-30 ° C. The reaction proceeds for 15-20 minutes, and then the reaction proceeds for 30-50 minutes at 50-90 ° C., and the reaction proceeds for 20-25 minutes under 30-50 ° C.,
As a specific method for separating the mixture containing the methanedisulfonate compound, an extraction solvent is added to proceed with extraction, the extract is bleached, and filtered through suction filtration, concentration, crystallization, and drying to obtain a methanedisulfonate compound. When selecting the temperature at the time of crystallization, methanedisulfo is characterized by first storing 10-15 minutes under -10 ~ 15 ℃ and cooling to -30 ~ -40 ℃ at a rate of 1-2 ℃ / min to complete the crystal. Methods for the synthesis of nate compounds.

According to claim 1,
The method for synthesizing a methanedisulfonate compound is characterized in that the molecular ratio between the formaldehyde compound and the alkenedisulfonic acid is (1-1.3): 1. delete delete According to claim 1,
The method for synthesizing a methanedisulfonate compound is characterized in that the molecular ratio of the dehydrating agent to the alkenesulfonic acid is (1-1.3): 1. According to claim 1,
The neutral dehydrating agent is an anhydrous magnesium sulfate, anhydrous sodium sulfate, anhydrous calcium sulfate, molecular sieve, any one or a combination of silica gel, a method for synthesizing a methanedisulfonate compound. According to claim 1,
The formaldehyde compound is a method for synthesizing a methanedisulfonate compound, characterized in that any one or a combination of paraformaldehyde, anhydrous formaldehyde, and trioxane. delete According to claim 1,
As the extraction solvent, any one of methylene chloride, chloroform, carbon tetrachloride, ethyl acetate, methyl acetate, and isopropyl acetate or a mixture thereof is used, and the mass ratio of the extraction solvent and the alkane disulfonic acid is (4-10): 1 Synthesis method of methane disulfonate compound. delete