Preparation methods of bis(fluorosulfonyl)imide and alkali metal salts thereof

Abstract

The invention relates to preparation methods of bis(fluorosulfonyl)imide and alkali metal salts thereof. The bis(fluorosulfonyl)imide is prepared by subjecting bis(chlorosulfonyl)imide to react with a fluorinating agent namely hydrogen fluoride. The alkaline metal salts of bis(fluorosulfonyl)imide is prepared by subjecting bis(chlorosulfonyl)imide and alkali metal halides to react with hydrogen fluoride taken as the fluorinating agent and the solvent. The preparation methods can reduce the raw material costs, reduce the material consumption and generation of wastes, improve the raw material utilization rate, product yield, and product purity; moreover, the product purification is easier, the preparation technology process is more concise and more efficient, and the preparation methods provides a very good technical foundation for massive industrial production of bis(fluorosulfonyl)imide and alkali metal salts thereof.

Description

technical field [0001] The invention relates to a preparation method of fluorine-containing compounds, in particular to bisfluorosulfonimide (HN[SO 2 F] 2 ) and alkali metal bisfluorosulfonylimide (MN[SO 2 F] 2 ; M=Li, Na, K, Rb, Cs). Background technique [0002] Bisfluorosulfonimide and bisfluorosulfonimide alkali metal salts, especially lithium salts, are important fluorine-containing compounds. They are used as key high-performance electrolyte materials in new energy devices such as lithium-ion batteries and supercapacitors. High industrial application value. [0003] The chemical structural formula of bisfluorosulfonimide and alkali metal salt of bisfluorosulfonimide is as follows: [0004] [0005] The patent CN101747242A of Huazhong University of Science and Technology first reacts sulfonamide with thionyl chloride and chlorosulfonic acid to obtain dichlorosulfonimide, then reacts it with antimony trifluoride to obtain difluorosulfonimide, and then reacts it w...

AI Technical Summary

Problems solved by technology

The method reported in this patent has the following problems: it involves four steps of chemical reaction and related purification steps, and the process flow is too long; the price of antimony fluoride, lithium perchlorate or lithium tetrafluoroborate is relatively expensive, and the cost of raw materials is too high; the consumption of raw materials is large And generate a lot of waste, including antimony trichloride, carbon dioxide, potassium perchlorate and organic solvents, etc.; the product has many impurities and is difficult to purify to meet the actual application standards

The method reported in this patent has the following problems: it involves three steps of chemical reaction and related purification steps, and the process flow is too long; bismuth trifluoride is expensive, even if it is recycled and used by chemical methods, the manufacturing cost is still too high; bisfluorosulfonimide There are too many by-products in the reaction with lithium carbonate in aqueous solution, and the yield of bisfluorosulfonimide lithium extracted from ethyl acetate is too low, and contains a large amount of impurities

However, the production process of the methods reported in these patents is too long, the consumption of raw materials is too large, too much waste is generated, the product yield is too low, and the manufacturing cost is too high

If the above problems are not resolved, it will hinder the large-scale application of bisfluorosulfonimide and its alkali metal salts, especially hinder its becoming the mainstream electrolyte material in new energy devices such as lithium-ion batteries and supercapacitors.

Images