阅读说明：本技术 一种氟代碳酸乙烯酯的制备方法 (Preparation method of fluoroethylene carbonate ) 是由 王海明 纪加明 翟涛 林涛 孙西船 朱会文 姚双开 于 2019-10-27 设计创作，主要内容包括：本发明公开了一种氟代碳酸乙烯酯的制备方法,包括以下步骤：1)在室温下将一定量的三乙胺三氢氟酸盐加入到容器中,加入适量的溶剂；2)再向溶液中加入一定量的三乙胺,PH达到5～7,搅拌使之均匀；3)再向溶液中滴加一定量的氯代碳酸乙烯酯,并在一定反应温度下反应,使用气象色谱监控反应过程；4)反应结束后,经过抽滤、洗涤、减压蒸馏后得到氟代碳酸乙烯酯；5)反应产生的滤饼经过回收得到三乙胺。本发明提供的氟代碳酸乙烯酯的制备方法,工艺简单、能耗低、环保、固废少、原子利用率高、收率高、适合大规模生产。(The invention discloses a preparation method of fluoroethylene carbonate, which comprises the following steps: 1) adding a certain amount of triethylamine trihydrofluoride salt into a container at room temperature, and adding a proper amount of solvent; 2) adding a certain amount of triethylamine into the solution, wherein the pH value reaches 5-7, and stirring to be uniform; 3) dropwise adding a certain amount of chloroethylene carbonate into the solution, reacting at a certain reaction temperature, and monitoring the reaction process by using a gas chromatography; 4) after the reaction is finished, obtaining fluoroethylene carbonate through suction filtration, washing and reduced pressure distillation; 5) and recycling a filter cake generated by the reaction to obtain triethylamine. The preparation method of fluoroethylene carbonate provided by the invention has the advantages of simple process, low energy consumption, environmental protection, less solid waste, high atom utilization rate and high yield, and is suitable for large-scale production.)

1. A preparation method of fluoroethylene carbonate is characterized in that: the method comprises the following steps:

s1: adding a certain amount of triethylamine trihydrofluoride salt into a container at room temperature, and adding a proper amount of solvent;

s2: adding a certain amount of triethylamine into the solution in the S1 until the pH value reaches 5-7, and stirring to be uniform;

s3: dropwise adding a certain amount of chloroethylene carbonate into the solution in the S2, reacting at a certain reaction temperature, and monitoring the reaction process by using a gas chromatography;

s4: after the reaction in S3 is finished, obtaining fluoroethylene carbonate through suction filtration, washing and reduced pressure distillation;

s5: the filter cake produced in S4 was recovered to obtain triethylamine.

2. The method for preparing fluoroethylene carbonate according to claim 1, wherein: the equivalent ratio of the triethylamine to the triethylamine trihydrofluoride salt added in the step S2 is 2.0: 1-2.1: 1.

3. The method for preparing fluoroethylene carbonate according to claim 1, wherein: the equivalent ratio of the chloroethylene carbonate to the triethylamine trihydrofluoric acid added in the step S3 is 2.85: 1-2.95: 1.

4. The method for preparing fluoroethylene carbonate according to claim 1, wherein: the reaction end point is that the content of the chloroethylene carbonate in the step S3 is less than 0.3%.

5. The method for preparing fluoroethylene carbonate according to claim 1, wherein: and the reaction time of the step S3 is 2-4 h.

6. The method for preparing fluoroethylene carbonate according to claim 1, wherein: the reaction temperature in the step S3 is 40-55 ℃.

7. The method for preparing fluoroethylene carbonate according to claim 1, wherein: the equivalent ratio of the triethylamine trihydrofluoride to the solvent in the step S1 is 1: 2-1: 3.

Technical Field

The invention relates to the field of lithium ion battery electrolyte additives, in particular to a preparation method of fluoroethylene carbonate which can be used as a lithium ion battery electrolyte additive.

Background

Fluoroethylene carbonate (FEC) is an important lithium ion battery electrolyte additive, an SEI film formed by electrolysis during initial charge and discharge has better performance, a compact structure layer is formed without increasing impedance, the electrolyte can be prevented from being further decomposed, and the low-temperature performance of the electrolyte is improved.

Fluoroethylene carbonate is now commonly synthesized in the chemical industry (CN102977070A, CN106854195A, etc.) by the fluorination reaction of chloroethylene carbonate (CEC) with solid fluoride (metal fluoride). But has the defects of long reaction time, troublesome treatment after reaction, lower utilization rate of fluorine ions, environmental pollution caused by solid wastes and the like.

Disclosure of Invention

The present invention is directed to a method for preparing fluoroethylene carbonate, which solves the above problems of the prior art.

In order to solve the technical problems, the invention provides the following technical scheme: a preparation method of fluoroethylene carbonate comprises the following steps:

s1: adding a certain amount of triethylamine trihydrofluoride salt into a container at room temperature, and adding a proper amount of solvent;

s2: adding a certain amount of triethylamine into the solution in the S1 until the pH value reaches 5-7, and stirring to be uniform;

s3: dropwise adding a certain amount of chloroethylene carbonate into the solution in the S2, reacting at a certain reaction temperature, and monitoring the reaction process by using a gas chromatography;

s4: after the reaction in S3 is finished, obtaining fluoroethylene carbonate through suction filtration, washing and reduced pressure distillation;

s5: the filter cake produced in S4 was recovered to obtain triethylamine.

As a preferable technical scheme of the present invention, the equivalent ratio of the triethylamine to the triethylamine trihydrofluoride salt added in the step S2 is 2.0:1 to 2.1: 1.

As a preferred technical solution of the present invention, the equivalent ratio of the chloroethylene carbonate and the triethylamine trihydrofluoric acid added in the step S3 is 2.85:1 to 2.95: 1.

In a preferred embodiment of the present invention, the reaction endpoint is that the content of chloroethylene carbonate in step S3 is less than 0.3%.

As a preferable technical scheme of the invention, the reaction time of the step S3 is 2-4 h.

In a preferred embodiment of the present invention, the reaction temperature in step S3 is 40 to 55 ℃.

In a preferred embodiment of the present invention, the equivalent ratio of the triethylamine trihydrofluoride to the solvent in step S1 is 1:2 to 1: 3.

Compared with the prior art, the invention has the beneficial effects that: the preparation method of fluoroethylene carbonate provided by the invention uses a common solvent as a reaction medium, does not need special requirements, is suitable for different factories, does not have potential safety hazard and increases the burden of factories (equipment such as a storage tank and the like does not need to be increased) compared with other specific organic solvents. Compared with other solid fluorinating agents, the triethylamine trihydrofluoride used as the fluorinating agent shortens the reaction time (homogeneous reaction), improves the reaction yield, reduces byproducts, reduces the solid waste of metal compounds and reduces the environmental pollution. The reaction temperature is 40-55 ℃, and compared with the reaction temperature of 80-100 ℃ in the traditional process, the method is safer and has lower energy consumption. The invention provides the preparation method of fluoroethylene carbonate, which has the advantages of simple process, low energy consumption, environmental protection, less solid waste, high atom utilization rate and high yield and is suitable for large-scale production.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.