Method for preparing fluoroethylene carbonate

Abstract

The invention discloses a method for preparing fluoroethylene carbonate, which is characterized by comprising: (1) reaction: adding chloroethylene carbonate, a fluoride and ion liquid in to a three-neck flask reactor in a certain a mount respectively, uniformly mixing the reactants by using a stirrer, performing reaction at a certain temperature and then performing the reaction at a constant temperature when the temperature reaches a required temperature, wherein the reaction temperature is between room temperature and 100 DEG C and the constant temperature is between 80 and 120 DEG C; and (2) purification of a coarse product: after the temperature is kept constant for a certain period of time, filtering the reaction solution, distilling the filtrate under a reduced pressure to obtain a coarse product, and rectifying the coarse product to obtain a product with a purity of 99.9 percent, wherein the residue of the d pressure distillation is the ion liquid, so the ion liquid can be used repeatedly for many times.

Description

technical field [0001] The invention relates to lithium ion battery technology; it is a preparation method for preparing fluoroethylene carbonate from monochloroethylene carbonate. Background technique [0002] Fluoroethylene carbonate is an additive used in the electrolyte of lithium-ion batteries. It can form an excellent SEI film with a compact structure without increasing impedance, effectively prevent the decomposition of the electrolyte, and improve the cycle life of lithium batteries. Therefore, it is more and more popular focus on. [0003] There are two main production methods of fluoroethylene carbonate. The main difference is the difference in raw materials: one uses a mixture of fluorine and nitrogen as a fluorinating agent to react with chloroethylene carbonate. Since the raw material used in this method is fluorine Gas is not only highly toxic and corrosive, but also the reactivity is not easy to control, and the requirements for reaction equipment are relativ...

AI Technical Summary

Problems solved by technology

[0003] There are two main production methods of fluoroethylene carbonate. The main difference is the difference in raw materials: one uses a mixture of fluorine and nitrogen as a fluorinating agent to react with chloroethylene carbonate. Since the raw material used in this method is fluorine gas, not only highly toxic and corrosive, but also difficult to control the reactivity, and the requirements for reaction equipment are relatively strict

Another kind uses sodium fluoride or potassium fluoride as fluorinating agent and reacts with chloroethylene carbonate, if this method does not use phase-transfer catalyst, reaction temperature is high, the time is long and conversion rate is low; Introduced in the patent number CN 101210005A A synthetic method using crown ether or polyethylene glycol as a phase transfer catalyst has been proposed. The advantages of this synthetic method are short reaction time, high yield and relatively low cost