Preparation method of lithium bis (fluorosulfonyl) imide and lithium bis (fluorosulfonyl) imide

Abstract

The invention discloses a preparation method of lithium bis (fluorosulfonyl) imide and the lithium bis (fluorosulfonyl) imide. Thionyl chloride, chlorosulfonic acid and sulfamic acid which are low inraw material cost and easy to obtain are used as raw materials; imidic acid is prepared under the condition of heating reflux reaction, potassium fluoride which is also used as a raw material and is low in cost and easy to obtain is used as a raw material to react with the imidic acid to obtain sylvite, potassium fluoride salt and anhydrous lithium salt react in a solvent to generate the lithium bis (fluorosulfonyl) imide, and the preparation process is low in energy consumption and has operation safety. And meanwhile, purification process treatment is carried out in each step, so that the high-purity and high-yield lithium bis (fluorosulfonyl) imide can be finally obtained, and the method is very suitable for being used as a process route for batch production of the lithium bis (fluorosulfonyl) imide.

Description

technical field [0001] The invention relates to the field of preparation of electrolytes in lithium-ion battery electrolytes, in particular to a method for preparing lithium bisfluorosulfonyl imide, and the invention also relates to lithium bisfluorosulfonyl imide prepared by the preparation method. Background technique [0002] In the current technology, lithium-ion batteries are widely used in electronic products, electric vehicles, and energy storage devices due to their high energy density. Therefore, for lithium-ion battery products, it is usually required to have excellent performances such as high capacity, long life, high rate performance and safety. Specifically, different compositions of electrolytes in lithium-ion batteries will largely lead to differences in the performance of lithium-ion batteries, especially in high and low temperature environments, electrolyte decomposition and side reactions will significantly affect the life of lithium-ion batteries , Self-...

AI Technical Summary

Problems solved by technology

[0004] At present, the existing preparation technologies at home and abroad have a long process route for preparing lithium bisfluorosulfonyl imide, complex product composition, difficult separation of entrained impurities in the product, and high cost, which affects the industrialization of the product.

For example, the invention patent with the publication number CN104495767A discloses a preparation method of lithium bisfluorosulfonyl imide, which needs to use a large amount of LiPF6 as the lithiation reagent. The total yield is only about 50%, and large-scale production cannot be realized; as the invention patent with the publication number CN110436424A also discloses a preparation method of lithium bisfluorosulfonyl imide, which requires the use of high-cost dichlorosulfonyl imide Amino acid as a raw material requires low temperature conditions of -80°C in the production process, which consumes a lot of energy. In addition, in the vacuum distillation process, it is necessary to collect fractions at 48-50°C / 650Pa. The actual operation is difficult, and large-scale production is also difficult.

Images