Method for preparing imidodisulfuryl fluoride lithium with villiaumite as fluorinating agent

Abstract

The invention provides a method for preparing imidodisulfuryl fluoride lithium with villiaumite as a fluorinating agent. The method comprises the following specific step: by taking imidodisulfuryl fluoride as a raw material, and a fluorinating agent as a complexing agent, performing a reaction in a polar organic solvent, thereby obtaining the imidodisulfuryl fluoride lithium, wherein the fluorinating agent comprises lithium fluoride or zinc fluoride; the fluorinating agent is 2-4 times of the weight parts of the imidodisulfuryl fluoride; the complexing agent comprises a lithium ion complexingagent or a zinc ion complexing agent; the complexing agent accounts for 0.5-5% of the weight parts of the fluorinating agent; and the polar organic solvent is selected from one or more of saturated carbonic esters, fluoro saturated carbonic esters, acetonitrile or N,N-dimethyl formamide. The imidodisulfuryl fluoride lithium prepared by using the method is low in toxin of reagents used in reactions, gentle in reaction condition, free of extreme condition such as high temperature and high pressure, low in equipment requirement and easy to achieve; in addition, the method provided by the invention is small in middle reaction, simple in later treatment, small in whole product preparation influence and very high in reaction yield, that is, up to 70-88%.

Description

technical field [0001] The invention relates to the technical field of bisfluorosulfonimide lithium electrolyte, in particular to a preparation method of bisfluorosulfonyl imide lithium using fluorine salt as a fluorinating agent. Background technique [0002] The high-nickelization of ternary power high-energy-density lithium-ion secondary batteries plays a decisive role in the rapid development of new energy vehicles and other power battery demand markets. However, the performance requirements of electrolytes are getting higher and higher, and high voltage and high Energy density, safety and other characteristics. [0003] The traditional lithium hexafluorophosphate electrolyte, which is easy to decompose at high temperature, limits its application in the field of high-voltage lithium-ion batteries. Lithium bisfluorosulfonyl imide (LiFSI) is favored by the market because it can improve the cycle and is suitable for both high and low temperatures. However, its synthesis pr...

AI Technical Summary

Problems solved by technology

[0004] At present, the methods for synthesizing LiFSI mainly include: (1) using SOCl 2 , ClSO 3 H and HSO 2 NH 2 Synthesis of HClSI followed by SbF 3 , AsF 3 , RhF 3 Wait for fluorination to obtain HFSI, then synthesize M-FSI with the corresponding metal salt, and finally pass LiBF 4 , LiClO 4 The method is cumbersome to replace with LiFSI, and the purity of the reaction intermediates in each step will have a great impact on the final product.

And As, Sb, Rh, etc. are highly toxic, if they cannot be removed, they will have a great impact on the performance of LiFSI

(2) Huazhong University of Science and Technology doctoral dissertation (2012) reported that HClSI was fluorinated to LiFSI by LiF / HF at -78°C. The advantage is that the by-products do not contain other metal salts. The post-treatment is relatively simple, but the yield is low. , and the reaction not only requires extremely high equipment, but also has a high risk of reaction

(3) CN 101980955 B Japan Catalyst Company provides a kind of from HClSI to Zn (FSI) 2 The method of preparing LiFSI through strong acidic ion exchange resin, but the yield is low and the post-treatment of the product is more complicated, and it is also difficult to ensure that the Zn content in the product is purified to a standard lower than 10ppm

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