A kind of purification method of succinonitrile

Abstract

The invention discloses a purification method of succinonitrile. The purification method of succinonitrile comprises the following steps: co-heating a crude succinonitrile product and a polar solventto melt the crude succinonitrile product, cooling the molten product to obtain succinonitrile crystals, and removing the residual solvent from the succinonitrile crystals to obtain high-purity succinonitrile, wherein the mass ratio of the polar solvent to the crude succinonitrile product is 0.02:1-0.15:1. According to the provided purification method, the purity of the crude succinonitrile productcan be effectively improved to 99.95% or higher by adopting the extremely trace polar solvent, so that high consumption of flammable, explosive and toxic solvents is effectively reduced, and generation of a large amount of waste liquid is also avoided. Compared with the existing purification process, the provided purification method has the advantages that production efficiency and production safety are obviously improved, energy consumption and waste liquid treatment pressure are reduced, and a more economical and environment-friendly new idea and way is provided for preparation of high-purity succinonitrile.

Description

technical field [0001] The application relates to the field of succinonitrile purification, in particular to a method for purification of succinonitrile. Background technique [0002] In 2002, Japan's Bridgestone Corporation developed the first generation of electrolyte additives for lithium-ion batteries, which laid the foundation for improving the cycle performance, high-temperature performance and safety performance of lithium-ion batteries. Lithium-ion battery electrolyte additives have the characteristics of strong pertinence and small dosage, and can significantly improve battery performance without changing the production process and without increasing production costs. As an important additive in the organic electrolyte of lithium-ion batteries, succinonitrile has the advantages of anti-bloating, improving the high-temperature cycle performance of the battery, and improving the electrochemical stability window, and has been valued by electrolyte manufacturers at home...

AI Technical Summary

Problems solved by technology

[0004] There are two existing succinonitrile purification processes, one is intermittent vacuum distillation purification, which requires higher temperature during the purification process, which is easy to cause polymerization and coking, etc., which affects product yield and quality, and consumes a lot of energy

Another kind of purification process is to adopt low-boiling point organic solvent recrystallization purification, the use amount of organic solvent is 0.5-5 times of the crude product weight of succinonitrile, and the organic solvent used is mostly flammable, explosive, toxic compound, the operation process is highly dangerous, the amount of waste liquid is huge, and it is not green enough

In the existing succinonitrile purification process, in order to obtain a purity of more than 99.95%, it is usually necessary to use the above two purification methods repeatedly or in combination, which not only consumes a lot of energy, but also has environmental protection and safety hazards