阅读说明：本技术 二氟磷酸盐基团化合物的合成方法 (Synthesis method of difluorophosphate group compound ) 是由 刘鹏 吴红松 葛建民 武利斌 闫彩桥 王军 郝俊 张民 侯荣雪 田丽霞 张茜 于 2019-11-18 设计创作，主要内容包括：二氟磷酸盐基团化合物的合成方法,属于电池电解液添加剂的技术领域,采用多元醇与三氯化磷为原料,二氯甲烷为溶剂,具体包括以下步骤：A、将多元醇加入到二氯甲烷中,加入负载有三乙胺的D101大孔树脂,然后控制温度-10～-15℃,向其中滴加三氯化磷,滴加时间2-3h,然后自然升温至0℃,保温处理0.5-1h,将反应液抽滤后,得到的中间产物；B、氮气保护下,将上述得到的中间产物与氟化钠加入到二氯甲烷中,升温至50-80℃,反应3-6h,然后经洗涤、干燥、减压去除溶剂,浓缩,得到二氟磷酸盐基团化合物。本发明合成二氟磷酸盐基团化合物的总收率高,达80-85％,GC纯度达99.8％左右,含氯杂质小于0.01％,环状杂质小于0.02％。(A synthetic method of difluorophosphate group compounds belongs to the technical field of battery electrolyte additives, adopts polyhydric alcohols and phosphorus trichloride as raw materials, adopts dichloromethane as a solvent, and specifically comprises the following steps: A. adding polyalcohol into dichloromethane, adding D101 macroporous resin loaded with triethylamine, controlling the temperature to be-10 to-15 ℃, dropwise adding phosphorus trichloride for 2-3h, naturally heating to 0 ℃, carrying out heat preservation treatment for 0.5-1h, and carrying out suction filtration on a reaction solution to obtain an intermediate product; B. under the protection of nitrogen, adding the intermediate product and sodium fluoride into dichloromethane, heating to 50-80 ℃, reacting for 3-6h, washing, drying, removing the solvent under reduced pressure, and concentrating to obtain the difluorophosphate group compound. The total yield of the difluorophosphate group compound synthesized by the method is high, and reaches 80-85%, the GC purity reaches about 99.8%, the chlorine-containing impurities are less than 0.01%, and the cyclic impurities are less than 0.02%.)

1. The synthesis method of the difluorophosphate group compound is characterized in that polyhydric alcohol and phosphorus trichloride are adopted as raw materials, and dichloromethane is adopted as a solvent, and the method specifically comprises the following steps:

A. adding polyalcohol into dichloromethane, adding D101 macroporous resin loaded with triethylamine, controlling the temperature to be-10 to-15 ℃, dropwise adding phosphorus trichloride for 2-3h, naturally heating to 0 ℃, carrying out heat preservation treatment for 0.5-1h, and carrying out suction filtration on a reaction solution to obtain an intermediate product;

B. under the protection of nitrogen, adding the intermediate product and sodium fluoride into dichloromethane, heating to 50-80 ℃, reacting for 3-6h, washing, drying, removing the solvent under reduced pressure, and concentrating to obtain the difluorophosphate group compound.

2. The method for synthesizing a difluorophosphate group compound according to claim 1, wherein the molar ratio of the polyhydric alcohol, phosphorus trichloride and triethylamine is 1: (2.3-6.1): (1.0-1.5).

3. The method of synthesizing a difluorophosphate group compound as recited in claim 1, wherein the molar ratio of the polyhydric alcohol to the sodium fluoride is 1: (4-10).

4. The method for synthesizing a difluorophosphate group compound as claimed in claim 1, wherein the polyhydric alcohol is one of ethylene glycol, glycerin, erythritol, xylitol and mannitol.

Technical Field

The invention belongs to the technical field of battery electrolyte additives, and relates to a synthetic method of a difluorophosphate group compound.

Background

The lithium ion battery has the advantages of small volume, good safety performance, light weight, high specific energy, high voltage, long service life, no pollution and the like which are incomparable with other chemical power supplies, and is a main power supply of portable electronic equipment such as mobile phones, palm computers, notebook computers, miniature video cameras, digital cameras and the like at present. In recent years, basic research and application development of lithium ion batteries have become one of the hot spots.

During initial charge of the lithium secondary battery, lithium ions are released from the positive electrode, transported to the negative electrode, and intercalated therein, and an SEI film is formed on the surface of the negative electrode to prevent reaction between lithium ions and a carbon negative electrode or other materials during charge and discharge. However, lithium ion batteries are easily decomposed in a high temperature environment, and cause an oxidation reaction of an electrolyte solution, so how to better improve the performance of the lithium ion batteries at high temperature, form a hard SEI film having good ionic conductivity on the surface of a negative electrode, inhibit the decomposition of the surface of the negative electrode during operation in the high temperature environment, prevent the oxidation of the electrolyte solution, and improve the cycle life and swelling of the batteries is worthy of intense research.

The difluorophosphate group compound can be used as an additive of a battery electrolyte, and the additive can oxidize difluorophosphate groups into fluorophosphates when a lithium battery is initially charged, so that a passive layer with excellent lithium ion conductivity on a positive electrode is more stable, and thus, the oxidation of the electrolyte solution can be prevented, and the cycle life and swelling phenomenon of the battery can be improved; and the electrolyte containing the additive can form a hard SEI film with good conductivity on the surface of the negative electrode. Therefore, the research of the difluorophosphate group compound is very meaningful.

The prior method for synthesizing difluorophosphate radical compounds mainly adopts the reaction of alcohol and phosphorus trichloride, and then adopts SbF₃In the presence of the catalyst, the reaction is heated to generate a difluorophosphate group compound, but the total yield is low.

Disclosure of Invention

The invention aims to provide a synthetic method of a difluorophosphate group compound, which has higher yield and high purity.

The technical scheme adopted by the invention for realizing the purpose is as follows:

the synthesis method of the difluorophosphate group compound adopts polyhydric alcohol and phosphorus trichloride as raw materials and dichloromethane as a solvent, and specifically comprises the following steps:

A. adding polyalcohol into dichloromethane, adding D101 macroporous resin loaded with triethylamine, controlling the temperature to be-10 to-15 ℃, dropwise adding phosphorus trichloride for 2-3h, naturally heating to 0 ℃, carrying out heat preservation treatment for 0.5-1h, and carrying out suction filtration on a reaction solution to obtain an intermediate product;

B. under the protection of nitrogen, adding the intermediate product and sodium fluoride into dichloromethane, heating to 50-80 ℃, reacting for 3-6h, washing, drying, removing the solvent under reduced pressure, and concentrating to obtain the difluorophosphate group compound.

The mol ratio of the polyhydric alcohol to the phosphorus trichloride to the triethylamine is 1: (2.3-6.1): (1.0-1.5).

The molar ratio of the polyol to the sodium fluoride is 1: (4-10).

The polyalcohol is one of ethylene glycol, glycerol, erythritol, xylitol, and mannitol.

The invention has the beneficial effects that:

the total yield of the difluorophosphate group compound synthesized by the method is high, and reaches 80-85%, the GC purity reaches about 99.8%, the chlorine-containing impurities are less than 0.01%, and the cyclic impurities are less than 0.02%.

Drawings

FIG. 1 is a H spectrum of the product compound of example 1.

FIG. 2 is a C spectrum of the product compound of example 1.

Figure 3 is the H spectrum of the product compound of example 2.

Figure 4 is the C spectrum of the product compound of example 2.

Figure 5 is the H spectrum of the product compound of example 3.

Figure 6 is the C spectrum of the product compound of example 3.

Figure 7 is the H spectrum of the product compound of example 4.

Figure 8 is the C spectrum of the product compound of example 4.

Figure 9 is the H spectrum of the product compound of example 5.

Figure 10 is the C spectrum of the product compound of example 5.

Detailed Description

The present invention will be further described with reference to the following examples.

Example 1

Adding 62g of ethylene glycol into 800mL of dichloromethane, adding D101 macroporous resin loaded with triethylamine, controlling the amount of triethylamine to be 101.2g, controlling the temperature to be minus 10 ℃, dropwise adding 315.8g of phosphorus trichloride into the dichloromethane for 2 hours, controlling the temperature to be constant at minus 10 ℃ in the dropwise adding process, naturally heating the temperature to 0 ℃, carrying out heat preservation treatment for 0.5 hour, carrying out suction filtration on reaction liquid to obtain an intermediate product, weighing 227.8g, calculating the yield to be 86.38%, determining the GC purity to be 99.85%, and determining that the chemical structural formula of the intermediate product is shown as

Under the protection of nitrogen, 220g of the intermediate product and 168g of sodium fluoride are added into 1000mL of dichloromethane, the temperature is raised to 50 ℃, the reaction is carried out for 6h, then the intermediate product is washed, dried, decompressed, the solvent is removed, and the product is concentrated, the product is obtained, the weighing is 157.3g, the calculated yield is 95.3%, the GC purity is 99.78%, the chlorine-containing impurity is 0.008%, the cyclic impurity is less than 0.016%, and the chemical structural formula of the product is determined as follows:

the overall yield over the two steps was calculated to be 82.3%.

Example 2

Adding 92g of glycerol into 1000mL of dichloromethane, adding D101 macroporous resin loaded with triethylamine, controlling the amount of the triethylamine to be 121.5g, then controlling the temperature to be minus 12 ℃, dropwise adding 439.4g of phosphorus trichloride into the dichloromethane for 2.5h, controlling the temperature to be constant at minus 12 ℃ in the dropwise adding process, then naturally heating to 0 ℃, carrying out heat preservation treatment for 50min, carrying out suction filtration on reaction liquid to obtain an intermediate product, weighing 344.2g, calculating the yield to be 87.22%, and measuring the chemical structural formula of the intermediate product to be 99.76% in GC purity

Under the protection of nitrogen, 340g of the intermediate product and 252g of sodium fluoride obtained above are added into 1200mL of dichloromethane, the temperature is raised to 60 ℃, the reaction is carried out for 4h, then the intermediate product is washed, dried, decompressed to remove the solvent, and concentrated to obtain 241.2g of product, the calculated yield is 94.6%, the GC purity is 99.81%, the chlorine-containing impurity is 0.005%, the cyclic impurity is less than 0.012%, and the chemical structural formula of the product is determined as follows:

the overall yield over the two steps was calculated to be 82.5%.

Example 3

Adding 122g of erythritol into 1300mL of dichloromethane, adding D101 macroporous resin loaded with triethylamine, controlling the amount of the triethylamine to be 131.5g, controlling the temperature to be 14 ℃ below zero, dropwise adding 576.7g of phosphorus trichloride into the erythritol for 155min, controlling the temperature to be constant at 14 ℃ below zero in the dropwise adding process, naturally heating the temperature to 0 ℃, carrying out heat preservation treatment for 42min, carrying out suction filtration on a reaction solution to obtain an intermediate product, weighing 447.3g, calculating the yield to be 85.12%, determining the GC purity to be 99.81%, and determining that the chemical structural formula of the intermediate product is shown in the specification

Under the protection of nitrogen, 440g of the intermediate product obtained in the previous step and 336g of sodium fluoride are added into 1600mL of dichloromethane, the temperature is raised to 70 ℃, the reaction is carried out for 5h, then the intermediate product is washed, dried, decompressed to remove the solvent, and concentrated to obtain the product, the weighing of which is 312.9g, the calculated yield is 94.9%, the GC purity is 99.78%, the chlorine-containing impurity is 0.006%, and the cyclic impurity is less than 0.014%, and the chemical structural formula of the product is determined as follows:

the overall yield over the two steps was calculated to be 80.7%.

Example 4

Adding 152g of xylitol into 2000mL of dichloromethane, adding D101 macroporous resin loaded with triethylamine, controlling the temperature to be-15 ℃, dropwise adding phosphorus trichloride for 3h, controlling the temperature to be constant at-15 ℃ in the dropwise adding process, naturally heating to 0 ℃, carrying out heat preservation treatment for 1h, carrying out suction filtration on reaction liquid to obtain an intermediate product, weighing 561.2g, calculating the yield to be 85.5%, and measuring the chemical structural formula of the intermediate product to be 99.76% in GC purity

Adding 560g of the intermediate product and 420g of sodium fluoride into 2400mL of dichloromethane under the protection of nitrogen, heating to 80 ℃, reacting for 6h, washing, drying, removing the solvent under reduced pressure, and concentrating to obtain 393.6g of a product, wherein the calculated yield is 93.8%, the GC purity is 99.81%, the chlorine-containing impurity is 0.007%, and the cyclic impurity is less than 0.015%, and the chemical structural formula of the product is determined as follows:

the overall yield over the two steps was calculated to be 80.2%.

Example 5

Adding 182g of mannitol into 2500mL of dichloromethane, adding D101 macroporous resin loaded with triethylamine, controlling the amount of the triethylamine to be 151g, then controlling the temperature to be 13 ℃ below zero, dropwise adding 837.5g of phosphorus trichloride into the mixture for 3h, controlling the temperature to be 13 ℃ below zero during the dropwise adding process to be constant, then naturally heating the mixture to 0 ℃, carrying out heat preservation treatment for 50min, carrying out suction filtration on reaction liquid to obtain an intermediate product, weighing 678g, calculating the yield to be 86.12%, and determining the GC purity to be 99.86%, wherein the chemical structural formula of the intermediate product is determined to be

670g of the intermediate product obtained above and 504g of sodium fluoride are added into 2800mL of dichloromethane under the protection of nitrogen, the temperature is raised to 65 ℃, the reaction is carried out for 4.5h, then the intermediate product is washed, dried, the solvent is removed under reduced pressure, and the intermediate product is concentrated to obtain 472.9g of the product, the calculated yield is 94.2%, the GC purity is 99.82%, the chlorine-containing impurity is 0.006%, and the cyclic impurity is less than 0.013%, and the chemical structural formula of the product is determined as follows:

the overall yield over the two steps was calculated to be 81.1%.