WO2019095245A1

WO2019095245A1 - Method for synthesizing methylene disulfonate compound

Info

Publication number: WO2019095245A1
Application number: PCT/CN2017/111504
Authority: WO
Inventors: 张民; 刘鹏; 王军
Original assignee: 石家庄圣泰化工有限公司
Priority date: 2017-11-17
Filing date: 2017-11-17
Publication date: 2019-05-23
Also published as: KR102101982B1; KR20190095100A

Abstract

The present invention discloses a method for synthesizing a methylene disulfonate compound, which is related to the technical field of battery electrolyte additives. The methylene disulfonate compound is synthesized by reacting an alkanedisulfonic acid with a formaldehyde compound in the presence of a dehydrating agent. The dehydrating agent is a neutral dehydrating agent. The alkanedisulfonic acid is a sulfonic acid compound represented by formula I. The molar ratio of the formaldehyde compound to the alkanedisulfonic acid is ≥1, in which R1 and R2 are independently a hydrogen atom, a C1-C4 alkyl optionally substituted with a halogen atom, n is an integer from 1 to 4, and when n is an integer from 2 to 4, n instances of R1 and n instances of R2 may be the same or different. The synthesis method of the present invention is simple and high in yield. The product has a high purity, low moisture content, and low acid value. The product can drastically increase the performance of a battery electrolyte.

Description

Method for synthesizing a methylene disulfonate compound

Technical field

The invention belongs to the technical field of battery electrolyte additives, and relates to a battery electrolyte additive, a methylene disulfonate compound, and particularly relates to a method for synthesizing a methylene disulfonate compound. The synthesis method of the invention is simple, the yield is high, the obtained product has high purity, low moisture content and low acid value, and the application to the battery electrolyte can greatly improve the performance of the electrolyte.

Background technique

The methylene disulfonate compound can be used as a pharmaceutical preparation for treating leukemia and the like in animals, and the sulfonic acid group contained in the structure can react with alcohol, phenol, thiol and the like under certain conditions, and its unique structure. It has a huge role in the synthesis of heterocyclic drugs. In recent years, with the development of new energy technologies, the application of methylene disulfonate compounds in lithium battery electrolyte additives has been gradually developed. The methylene disulfonate compound is used in lithium battery electrolyte additives, which can be remarkable. Improve battery performance, increase battery rechargeability and cycle characteristics. However, the moisture content and acid value of the methylene disulfonate compound prepared by the prior method are relatively high, and are applied to the battery to cause decomposition, flatulence and bulging of the electrolyte, which not only fails to improve the performance of the battery, but also significantly The performance of the battery is lowered, and therefore, the moisture content and acid value of the added additive must be strictly controlled.

Existing methods for preparing methylene disulfonate compounds include several of the following methods:

(1) First, a sulfonyl chloride is reacted with silver carbonate to obtain silver sulfonate, and then silver sulfonate is reacted with diiodomethane, and R is a hydrogen atom or a methyl group:

However, the raw materials used in this method are expensive and slow in reaction with silver carbonate and diiodomethane, and the yield is low.

(2) Alkane disulfonic acid or the like is reacted with methylene diacetate or the like, and R' and R" are independently a hydrogen atom or an alkyl group:

However, the raw material diacetate used in this production method is very expensive and not easily available, and the alkane disulfonic acid which is additionally used as a raw material is also expensive to affect its industrial application.

(3) at least one of a formaldehyde compound and an alkali metal salt of an alkanedisulfonate (such as Formula 1) and an alkane disulfonate alkaline earth metal salt (such as Formula 2) each represented by a specific formula in the presence of a dehydrating agent. Alkane disulfonate reaction:

This method reduces the production cost to some extent, but the two raw materials of the alkane disulfonic acid alkali metal salt (such as Formula 1) and the alkane disulfonate alkaline earth metal salt (such as Formula 2) are still expensive and difficult to obtain.

(4) Preparing a formaldehyde compound with an alkanedisulfonic acid in the presence of a dehydrating agent:

This method reduces the production cost to a certain extent, but the yield is low and can only reach about 50%. Moreover, the obtained product has high moisture content and high acid value, affecting the performance applied to the battery, and has no industrial value.

Summary of the invention

In order to solve the above problems, the present invention provides a method for synthesizing a methylene disulfonate compound, which has a mild and stable synthesis process, and greatly improves the yield and product quality. The structural formula of the methylene disulfonate compound of the present invention is as shown in the following II: R ₁ and R _{2 are} independently a hydrogen atom or a C _1-4 alkyl group in which a hydrogen atom may be substituted by a halogen atom; n is 1 to 4 An integer; 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 solution adopted by the present invention for achieving the purpose is:

A method for synthesizing a methylene disulfonate compound, which is synthesized by reacting an alkanedisulfonic acid with a formaldehyde compound in the presence of a dehydrating agent, wherein the dehydrating agent is a neutral dehydrating agent, and the alkane disulfonic acid is used. The sulfonic acid compound of the formula I, controlling the molar ratio of the formaldehyde compound to the alkanedisulfonic acid ≥1; wherein R ₁ and R _{2 are} independently a hydrogen atom or a C _1-4 alkane which may be substituted by 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 may be the same or different;

The molar ratio of the formaldehyde compound to the alkanedisulfonic acid is (1 - 1.3): 1. Formaldehyde compound Do not use too much, otherwise it will increase the moisture content of the final product, so the molar ratio to the alkanedisulfonic acid should be controlled to be (1-1.3):1.

The reaction temperature was controlled to be less than 100 ° C, and the atmospheric pressure reaction time was 1-2 h. The reaction temperature is controlled to be less than 100 ° C in order to better remove moisture, and to prevent the partial contact of the methylene disulfonate compound caused by condensation after evaporation of water to entrap moisture into the crystal, resulting in an increase in the moisture content of the product.

The three-stage temperature control method is adopted in the reaction process. The temperature in the first stage is the lowest, the temperature in the third stage is second, and the temperature in the second stage is the highest. Specifically: the temperature is controlled at 20-30 ° C for 15-20 min, then the temperature is controlled at 50-90 ° C for 30-50 min, then the temperature is controlled at 30-50 ° C for 20-25 min, but the temperature of the third stage is higher than the first The height of one stage is lower than that of the second stage. The low temperature reaction at 20-30 °C is to make the reaction process mild, avoiding the reaction being too intense at high temperature, causing by-product formation and water doping, which acts as a buffer; then controlling the high temperature reaction at 50-90 °C is In order to promote the reaction, the conversion rate is accelerated; finally, at a low temperature of 30-50 ° C, it is a slowing process of the reaction, allowing it to stabilize the continuous reaction, while the final stage of cooling can prevent the cooling time from being long and the temperature difference is large after the reaction is completed. The crystal encapsulates moisture defects. Three-stage temperature control can greatly shorten the response

The molar ratio of the dehydrating agent to the alkanedisulfonic acid is (1-1.3):1.

The neutral dehydrating agent is selected from one or a combination of anhydrous magnesium sulfate, anhydrous sodium sulfate, anhydrous calcium sulfate, molecular sieves, and silica gel.

The formaldehyde compound is selected from the group consisting of paraformaldehyde, anhydrous formaldehyde, and three

One or several combinations of alkane.

The mixture containing the methylene disulfonate compound is separated by adding an extractant thereto for extraction, and then the extract is subjected to decolorization, suction filtration, concentration, crystallization, and drying to obtain a methylene disulfonate compound.

The extracting agent is a mixture of one or more of dichloromethane, chloroform, carbon tetrachloride, ethyl acetate, methyl acetate and isopropyl acetate, and the mass ratio of the extracting agent to the alkanedisulfonic acid is (4-10): 1. The amount of extractant is the key to achieve the extraction effect. Too little will make the extraction incomplete, resulting in low yield; too much will increase the difficulty and time of subsequent extraction agent, and will also cause partial hydrolysis, affecting the yield and quality of the product. .

The crystallization is carried out by continuous cooling, and is kept at -10 to -15 ° C for 10-15 minutes, and then cooled to -30 to -40 ° C at a rate of 1-2 ° C / min to complete crystallization. The control of the crystallization mode and conditions of the present invention is to prevent entrapment of water during the crystallization process, resulting in an increase in moisture content and affecting the properties and properties of the product.

The beneficial effects of the invention are:

The method for producing the methylene disulfonate compound has the advantages of low cost and remarkable economic benefit; the reaction process is mild and stable; the alkanedisulfonic acid can be solid or liquid, and the reactant can be directly reacted or in the solvent. The reaction is carried out in a simple and easy process. The advantage of the reaction yield of the alkanedisulfonic acid and the formaldehyde compound is more than 75%, and the yield is improved by more than 25% compared with the prior art, and a qualitative leap is achieved. The acid value and moisture content are also greatly reduced, and this effect causes the flatulence and bulging of the battery to be lowered.

The invention particularly emphasizes the use of a neutral dehydrating agent, which is to promote the reaction and increase the conversion rate on the one hand, and to combine with water if an acidic dehydrating agent such as phosphorus pentoxide is used in our research. After formation of a slightly acidic environment, this will lead to a certain degree of hydrolysis of the synthesized methylene disulfonate compound, which ultimately leads to a decrease in yield, which is why the prior art uses a formaldehyde compound and an alkanedisulfonic acid to synthesize a yield. The important reason that the low can only reach about 50% (such as the patent document with the application number of 200780014629.X), the micro-environment is easily overlooked, and the seemingly insignificant influence is very large. At present, there is no research on this aspect. Prior art has not been found The key reason, at the same time, the use of acidic dehydrating agent will also make the synthesized acid value of the methylene disulfonate compound higher, affecting the performance in the battery; if the alkaline dehydrating agent is used, it will not only inhibit the positive reaction. It is carried out, and a side reaction of the sulfonic acid compound with the alkaline substance may occur, which seriously affects the yield and quality of the product.

The present invention particularly emphasizes that the molar ratio of the formaldehyde compound to the alkanedisulfonic acid is ≥1, and the amount of the formaldehyde must be excessive. The purpose is not to complete the reaction of the alkanedisulfonic acid, but to create a disulfonic acid. The stable presence of the methyl ester compound avoids the problem of yield reduction due to hydrolysis of the methylene disulfonate compound and avoids an increase in the acid value. If the amount of the alkanedisulfonic acid is excessive, the above effect cannot be achieved. The excess of the alkanedisulfonic acid causes the partial hydrolysis of the methylene disulfonate compound to destroy the stable environment of the methylene disulfonate compound, and the alkane II An excess of sulfonic acid will result in a high acid value. This is also the reason why the prior art has a low yield and a high acid value.

Detailed ways

The invention will now be further described in conjunction with specific embodiments.

First, the specific embodiment

Example 1

In a reaction vessel equipped with a stirrer, a condenser and a thermometer, 1760 g (10 mol) of methanedisulfonic acid and 1204 g (10 mol) of anhydrous magnesium sulfate were added, and 359 g (11 mol) of 92% was added thereto at room temperature with stirring. POM, after the addition is completed, keep stirring, first control the temperature at 20-30 ° C for 15 min, then control the temperature 50-90 ° C reaction for 30 min, then control the temperature 35-45 ° C reaction 20min, cool to room temperature, add 7050g Dichloromethane is extracted, the extract is decolorized by adding activated carbon, then filtered, concentrated, placed at -10 ° C for 10 min, then cooled to -30 ° C at a rate of 1 ° C / min, complete crystallization, filtration, drying under reduced pressure Dry, 1447.6 g of an off-white crystal methane methanesulfonate was obtained, and the yield was calculated to be 77%. Nuclear magnetic spectrum 1H-NMR (400MHz, CD3CN) δ (ppm): 5.33 (s, 2H), 6.00 (s, 2H). The moisture content was measured to be 10 ppm and the acid value was 15 ppm.

Example 2

In a reaction vessel equipped with a stirrer, a condenser and a thermometer, 1900 g (10 mol) of 1,2-ethanedisulfonic acid and 1846 g (13 mol) of anhydrous sodium sulfate were added, and 423 g (13 mol) was added thereto at room temperature with stirring. 92% paraformaldehyde, after the addition, keep stirring, first control the temperature at 23-25 ° C for 20min, then control the temperature 60-80 ° C reaction for 40min, then control the temperature 30-40 ° C reaction for 25min, cool to room temperature Adding 9500 g of chloroform (which can be replaced by one or more of the same mass of carbon tetrachloride, ethyl acetate, methyl acetate, and isopropyl acetate) for extraction, and the extract is added to the activated carbon for decolorization. Then, suction filtration, concentration, incubated at -15 ° C for 15 min, then cooled to -40 ° C at a rate of 2 ° C / min, complete crystallization, filtration, drying under reduced pressure, to obtain 1585.7 g white crystals 1,2-B Methyl alkanedisulfonate was calculated to have a yield of 78.5%. Nuclear magnetic spectrum 1H-NMR (400 MHz, CD3CN) δ (ppm): 3.83 (s, 4H), 5.63 (s, 2H). The moisture content was 13 ppm and the acid value was 15 ppm.

Example 3

In a reaction vessel equipped with a stirrer, a condenser and a thermometer, 2600 g (10 mol) of 4,4-dipropylmethanedisulfonic acid and 1440 g (12 mol) of anhydrous magnesium sulfate (which can be replaced with an equimolar anhydrous sulfuric acid) Sodium, anhydrous calcium sulfate, molecular sieve, one or more of silica gel), 326g (10mol) of 92% paraformaldehyde (can be replaced by equimolar anhydrous formaldehyde or three) at room temperature and stirring

Alkane), after the addition, keep stirring, first control the temperature at 25-28 ° C for 18min, then control the temperature 70-90 ° C reaction for 50min, then control the temperature 40-50 ° C reaction 20min, cool to room temperature, add 26000g The carbon tetrachloride is extracted, the extract is decolorized by adding activated carbon, then filtered, concentrated, placed at -13 ° C for 13 min, then cooled to -35 ° C at a rate of 1.5 ° C / min, complete crystallization, filtration, 40 ° C After drying at 10 mmHg for 3 hours, 2110.7 g of crystals, that is, methylene methyl 4,4-dipropylmethanedisulfonate, was obtained, and the yield was calculated to be 77.6%. The nuclear magnetic spectrum is ¹ H-NMR (400 MHz, CD3CN) δ (ppm): 5.72 (s, 2H), 2.33 (s, 4H), 1.33 (s, 4H) 0.90 (s, 6H). The moisture content was measured to be 15 ppm and the acid value was 17 ppm.

Comparative example 1

Compared with Example 1, an acidic catalyst such as phosphorus pentoxide was used, and the other conditions were the same, and 996.4 g of a product was obtained, the calculated yield was 53%, the detected moisture content was 58 ppm, and the acid value was 70 ppm.

Comparative example 2

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

Comparative example 3

In a 200 ml four-necked flask equipped with a stirrer, a condenser and a thermometer, 8.8 g (0.05 mol) of methane disulfonic acid and 7.1 g (0.05 mol) of phosphorus pentoxide were placed. 1.6 g (0.05 mol) of 92% paraformaldehyde was added to the mixture at room temperature with stirring. After the addition was completed, the mixture was heated to 120 ° C and stirred for 1 h. The mixture was then cooled to room temperature, and 100 g of dichloromethane was added thereto. After stirring for 1 h, the insoluble material was filtered off. The obtained filtrate was concentrated to obtain crystals, and the obtained crystals were dried at 40 ° C and 10 mmHg for 6 hours to obtain 4.7 g of methylene methanesulfonate methane as a pale brown crystal. The yield was 50%, the detected moisture content was 65 ppm, and the acid value was 86 ppm. .

Comparative example 4

In a 200 ml four-necked flask equipped with a stirrer, a condenser and a thermometer, 9.5 g (0.05 mol) of 1,2-ethanedisulfonic acid and 8.5 g (0.06 mol) of phosphorus pentoxide were placed. 2.0 g (0.06 mol) of 92% paraformaldehyde was added to the mixture at room temperature with stirring. After the addition was completed, the mixture was heated to 120 ° C and stirred for 1 h. The mixture was then cooled to room temperature and 100 g of two were added thereto. Methyl chloride. After stirring for 1 h, the insoluble material was filtered off. The obtained filtrate was concentrated to obtain crystals, and the obtained crystals were dried at 40 ° C and 10 mmHg for 6 hours to obtain 7.0 g of light brown crystals of methylene chloride of 1,2-ethanedisulfonate, the calculated yield was 69.2%, and the detected moisture content was 73 ppm. , acid value of 90ppm.

Second, the application test

The development and application of battery additives is to improve and improve the performance of the battery. The acid value and moisture content of the additive affect the performance of the battery, which also affects the life of the electrolyte. If the acid value and moisture content are high, it is easy to cause acid hydrolysis and deterioration. The gas is scrapped and affects the high and low temperature stability of the battery. The methylene disulfonate compound prepared above is added as an additive to the same electrolyte in the same amount, and the performance of the battery is tested for comparison and verification.

The product obtained in the above "A. Specific Example" is added to the base electrolyte in an amount of 1% by weight of the base electrolyte, and the electrolyte of the battery of the base electrolyte is: DC/EMC = 1/3, LiPF ₆ : 1.1M FEC, PST, the positive and negative current collectors are distributed in aluminum foil and copper foil. The diaphragm is made of ceramic diaphragm to form a soft pack battery. After injecting the electrolyte, it is assembled into a soft pack battery in the glove box, and it is tested after standing for 8 hours. The application performance was tested and the results were as follows.

1. The battery was activated by charging and discharging at a temperature of 25 ° C at a constant temperature of 25 ° C, respectively, and then charged and discharged at 1 °C under a cycle of 45 ° C. The cycle test results are shown in Table 1.

Table 1

2. Battery discharge retention rate at different rates: discharge the battery to 3.0V with a constant current of 0.5C, and put it on hold 5min, then charged to a voltage of 4.5V or more with a constant current of 0.5C, and charged at a constant voltage, the current is 0.05C, left for 5min, and then discharged at a constant current of 0.2C, 1C, 1.5C, 2C to a voltage of 3.0V. Record the discharge capacity under the conditions of 0.2C, 1C, 1.5C, 2C as D1, record the discharge capacity at 0.2C as D0, and based on the discharge capacity at 0.2C, the discharge capacity retention rate through the battery = [(D1-D0) ) / D0] × 100% of the formula to calculate the discharge capacity retention rate of the battery at different rates (measured 15 batteries, take the average), the battery capacity at 25 ° C conditions, the discharge capacity retention rate at different rates as shown 2 is shown.

Table 2

3, battery high-temperature storage performance evaluation: 60 ° C / 30D and 85 ° C / 7D storage performance test, the following list 3 is the battery after the standard charge and discharge, then stored at 60 ° C for 30 days and 85 ° C for 7 days, then measure the battery capacity retention Rate and capacity recovery rate.

table 3

4, battery low-temperature storage performance evaluation; Table 4 is to put the battery in the low temperature box, separately controlled The temperature was -30 ° C or -40 ° C, the hold time was 240 min, and then the capacity retention of the battery was measured.

Table 4

Claims

A method for synthesizing a methylene disulfonate compound, which is obtained by reacting an alkanedisulfonic acid with a formaldehyde compound in the presence of a dehydrating agent, and then separating the mixture containing the methylene disulfonate compound, and is characterized by Wherein the dehydrating agent is a neutral dehydrating agent, the alkanedisulfonic acid is a sulfonic acid compound of the formula I, and the molar ratio of the formaldehyde compound to the alkanedisulfonic acid is controlled to be ≥1; wherein R 1 and R 2 is independently a C 1-4 alkyl group in which a hydrogen atom or a hydrogen atom may be substituted by a halogen atom; n is an integer of 1 to 4; and when n is an integer of 2 to 4, n R 1 and n R 2 Can be the same or different;
The method for synthesizing a methylene disulfonate compound according to claim 1, wherein the molar ratio of the formaldehyde compound to the alkanedisulfonic acid is (1 to 1.3):1.
The method for synthesizing a methylene disulfonate compound according to claim 1, wherein the reaction temperature is controlled to be less than 100 ° C and the reaction time is 1-2 h.
The method for synthesizing a methylene disulfonate compound according to claim 3, wherein a three-stage temperature control mode is adopted in the reaction process, wherein the temperature in the first stage is the lowest, and the temperature in the third stage is second. The second stage has the highest temperature.
The method for synthesizing a methylene disulfonate compound according to claim 1, wherein the molar ratio of the dehydrating agent to the alkanedisulfonic acid is (1 to 1.3):1.
The method for synthesizing a methylene disulfonate compound according to claim 1, wherein the neutral dehydrating agent is selected from the group consisting of anhydrous magnesium sulfate, anhydrous sodium sulfate, anhydrous calcium sulfate, molecular sieve, and silica gel. One or several combinations.
The method for synthesizing a methylene disulfonate compound according to claim 1, wherein the formaldehyde compound is selected from the group consisting of paraformaldehyde, anhydrous formaldehyde, and three
One or several combinations of alkanes.
The method for synthesizing a methylene disulfonate compound according to claim 1, wherein the separation of the mixture containing the methylene disulfonate compound is carried out by adding an extractant thereto for extraction, and then The extract is subjected to decolorization, suction filtration, concentration, crystallization, and drying to obtain a methylene disulfonate compound.
The method for synthesizing a methylene disulfonate compound according to claim 1, wherein the extracting agent is dichloromethane, chloroform, carbon tetrachloride, ethyl acetate, methyl acetate or acetic acid. A mixture of one or more of the propyl esters, the mass ratio of the extractant to the alkanedisulfonic acid is (4-10):1.
The method for synthesizing a methylene disulfonate compound according to claim 1, wherein the crystallization is carried out by means of continuous cooling, and the temperature is maintained at -10 to 15 ° C for 10-15 minutes, and then 1-2. The rate of °C/min was lowered to -30 to -40 ° C to complete crystallization.