阅读说明：本技术 一种利用有机金属锂试剂制备双氟磺酰亚胺锂的方法 (Method for preparing lithium bis (fluorosulfonyl) imide by using organic metal lithium reagent ) 是由 梁海波 谢文健 苏秋铭 张梦 辛伟贤 陈新滋 于 2020-05-12 设计创作，主要内容包括：本发明公开了一种利用有机金属锂试剂制备双氟磺酰亚胺锂的方法,包括以下步骤:S1以有机金属锂试剂为原料,与双氟磺酰亚胺酸进行混合反应得到双氟磺酰亚胺锂粗品。S2对粗品进行减压抽干,加入双氟磺酰亚胺锂的不良有机溶剂洗涤多次,再真空抽干得固体。S3向固体中加入有机溶剂萃取,过滤,浓缩,向浓缩液中加入低极性非质子溶剂,静止结晶,过滤,晶体真空干燥便得到双氟磺酰亚胺锂盐。以上制备步骤在惰性气体保护下进行无水操作。本发明提供的制备方法能制备高纯度的双氟磺酰亚胺锂,产率高,而且产品质量稳定,有效降低产品中的钾离子、钠离子、钙离子、氟离子、氯离子、硫酸根离子和水份等杂质含量。(The invention discloses a method for preparing bis (fluorosulfonyl) imide lithium by using an organic metal lithium reagent, which comprises the following step of S1, mixing and reacting the organic metal lithium reagent with bis (fluorosulfonyl) imide acid to obtain a crude bis (fluorosulfonyl) imide lithium product. S2, decompressing and pumping the crude product, adding a poor organic solvent of lithium bis (fluorosulfonyl) imide, washing for multiple times, and then performing vacuum pumping to obtain a solid. S3 adding organic solvent into the solid for extraction, filtering, concentrating, adding low-polarity aprotic solvent into the concentrated solution, standing for crystallization, filtering, and drying the crystal in vacuum to obtain the lithium bis (fluorosulfonyl) imide. The preparation steps are carried out under the protection of inert gas and without water. The preparation method provided by the invention can be used for preparing high-purity lithium bis (fluorosulfonyl) imide, has high yield and stable product quality, and effectively reduces the content of impurities such as potassium ions, sodium ions, calcium ions, fluoride ions, chloride ions, sulfate ions, moisture and the like in the product.)

1. A method for preparing lithium bis (fluorosulfonyl) imide by using an organometallic lithium reagent, comprising the steps of;

s1, taking an organic metal lithium reagent as a raw material, and carrying out mixed reaction with bis (fluorosulfonyl) imide acid at low temperature to obtain a crude bis (fluorosulfonyl) imide lithium product;

s2, performing decompression and suction drying on the crude product, adding a poor organic solvent of lithium bis (fluorosulfonyl) imide for washing for multiple times, and performing vacuum suction drying to obtain a solid;

and S3, adding an organic solvent into the solid for extraction, filtering, concentrating, adding a low-polarity aprotic solvent into the concentrated solution, standing for crystallization, filtering, and drying the crystal in vacuum to obtain the lithium bis (fluorosulfonyl) imide.

2. The method of claim 1, wherein the organometallic lithium reagent in step S1 comprises alkyl lithium, alkynyl lithium, aryl lithium.

3. The method of claim 2, wherein the alkyl lithium comprises one or more combinations of methyl lithium, ethyl lithium, n-butyl lithium, iso-butyl lithium, tert-butyl lithium, and 1,5 dilithiopentane.

4. The method of claim 2, wherein the lithium alkynyl comprises one or more combinations of lithium ethynyl, dilithium ethynyl, and 1,3 dilithiopropylene.

5. The method of claim 2, wherein the aryl lithium comprises one or more combinations of phenyl lithium, benzyl lithium, phenylethynyl lithium, 2,4, 6-trimethylbenzene lithium, and naphthalene lithium.

6. The method for preparing lithium bis (fluorosulfonyl) imide using organometallic lithium reagent according to claim 1, wherein the low temperature condition in S1 is 0 to-78 ℃, preferably 0 to-20 ℃.

7. The method for preparing lithium bis (fluorosulfonyl) imide from organometallic lithium reagent according to claim 1, wherein the molar ratio of reaction between bis (fluorosulfonyl) imide acid and organometallic lithium reagent in S1 is 1.0: 1.0-3.0, preferably 1.0: 1.0-1.5.

8. The method for preparing lithium bis (fluorosulfonyl) imide using organometallic lithium reagent according to claim 1, wherein the reaction time in step S1 is 1-6 hours, preferably 2-4 hours.

9. The method for preparing lithium bis (fluorosulfonyl) imide using organometallic lithium reagent according to claim 1, wherein the vacuum degree of the vacuum pumping in step S2 is 4-10 torr, preferably 3-5 torr, and the temperature is 0-40 ℃, preferably 20-40 ℃.

10. The method for preparing lithium bis (fluorosulfonyl) imide using organometallic lithium reagent as claimed in claim 1, wherein said poor organic solvent in S2 is selected from n-hexane, cyclohexane, cyclopentane, dichloromethane, chloroform, dichloroethane, bromoethane, dibromoethane, toluene, o-xylene, p-xylene, or their combination.

11. The method of claim 1, wherein the extraction solvent in S3 comprises esters, carbonates, ethers, alcohols, ketones, nitriles, wherein the esters are selected from one or more of methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, and vinyl acetate, the carbonates are selected from one or more of dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, vinyl carbonate, propylene carbonate, fluoroethylene carbonate, and difluoroethylene carbonate, and the ethers are selected from one or more of diethyl ether, propyl ether, isopropyl ether, butyl ether, isobutyl ether, tetrahydrofuran, tert-butyl methyl ether, methyl tetrahydrofuran, dioxolan, dioxane, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, diethanol monoethyl ether, diethylene glycol monoethyl ether, and mixtures thereof, Ethylene glycol diethyl ether, propylene glycol methyl ether, propylene glycol diethyl ether, the alcohol is selected from one or more combinations of methanol, ethanol, propanol, isopropanol, butanol and isobutanol, the ketone is selected from one or more combinations of acetone, butanone, methyl ethyl ketone, methyl tert-butyl ketone and pyrrolidone, and the nitrile is selected from one or more combinations of acetonitrile, propionitrile and isopropionitrile.

12. The method for preparing lithium bis (fluorosulfonyl) imide using organometallic lithium reagent according to claim 1, wherein the concentration in S3 is performed under a vacuum of 4-10 torr and at a temperature of 0-50 ℃, preferably at a temperature of 25-35 ℃, and the concentration is performed to 1/6-1/3 of the volume of the original solution.

13. The method of claim 1, wherein the low polar aprotic solvent in step S3 is selected from one or more of n-hexane, cyclohexane, cyclopentane, dichloromethane, chloroform, dichloroethane, bromoethane, dibromoethane, toluene, o-xylene, and p-xylene.

14. The method for preparing lithium bis (fluorosulfonyl) imide using organometallic lithium reagent according to claim 1, wherein the crystallization time in step S3 is 12-48 hours, preferably 16-24 hours, and the crystallization temperature is-20 to-10 ℃.

15. The method for preparing lithium bis (fluorosulfonyl) imide using organometallic lithium reagent according to claim 1, wherein the vacuum drying degree in step S3 is 3 to 4 torr, and the temperature is 10 to 50 ℃, preferably 20 to 40 ℃.

Technical Field

The invention relates to a method for preparing lithium bis (fluorosulfonyl) imide by using an organic metal lithium reagent.

Background

The lithium bis (fluorosulfonyl) imide can be used in various fields, for example, as an additive for secondary lithium ion battery electrolyte to improve the cycle performance of lithium ion batteries, and can also be used as an electrolyte for primary batteries; can be used as a polymerization catalyst; can also be used as an antistatic agent in the industrial field. The results of the prior art show that lithium hexafluorophosphate (LiPF)₆) Is a currently more successful commercial lithium salt electrolyte, but LiPF₆The heat stability and the chemical stability are poor, and the lithium bis (fluorosulfonyl) imide has better stability, excellent low-temperature performance and good hydrolysis resistance compared with the lithium bis (fluorosulfonyl) imide, so that the lithium bis (fluorosulfonyl) imide has the potential to replace lithium hexafluorophosphate to become a new generation of secondary lithium ion battery electrolyte. Therefore, the simple preparation of high-purity lithium bis (fluorosulfonyl) imide has become a major development direction in the field of lithium ion battery electrolytes in recent years.

Disclosure of Invention

The invention aims to overcome the technical defects and provide a method for preparing lithium bis (fluorosulfonyl) imide by using an organic metal lithium reagent.

The preparation method comprises the following steps;

s1, taking an organic metal lithium reagent as a raw material, and carrying out mixed reaction with bis (fluorosulfonyl) imide acid at low temperature to obtain a crude bis (fluorosulfonyl) imide lithium product;

s2, performing decompression and suction drying on the crude product, adding a poor organic solvent of lithium bis (fluorosulfonyl) imide for washing for multiple times, and performing vacuum suction drying to obtain a solid;

and S3, adding an organic solvent into the solid for extraction, filtering, concentrating, adding a low-polarity aprotic solvent into the concentrated solution, standing for crystallization, filtering, and drying the crystal in vacuum to obtain the lithium bis (fluorosulfonyl) imide.

In a further embodiment, the organometallic lithium reagent in step S1 includes alkyl lithium, alkynyl lithium, and aryl lithium.

In a further embodiment, the alkyllithium comprises one or more combinations of methyllithium, ethyllithium, n-butyllithium, isobutyllithium, tert-butyllithium, and 1, 5-dilithiopentane.

In a further embodiment, the lithium alkynyl includes one or more combinations of lithium ethynyl, dilithium ethynyl, and 1, 3-dilithiopropylene.

In a further embodiment, the aryl lithium includes one or more of phenyl lithium, benzyl lithium, phenylethynyl lithium, 2,4, 6-trimethylbenzene lithium, and naphthalene lithium.

In a further scheme, the low temperature condition in S1 is 0 to-78 ℃, and the preferable temperature is 0 to-20 ℃.

In a further scheme, the molar ratio of the reaction of the bis-fluorosulfonyl imide acid and the organometallic lithium reagent in S1 is 1.0: 1.0-3.0, and the preferable ratio is 1.0: 1.0-1.5.

In a further scheme, the reaction time in the step S1 is 1-6 hours, and preferably 2-4 hours.

In a further scheme, the vacuum degree of the reduced pressure pumping in the step S2 is 4-10 torr, preferably 3-5 torr, and the temperature is 0-40 ℃, preferably 20-40 ℃.

In a further embodiment, the poor organic solvent in S2 is selected from one or more of n-hexane, cyclohexane, cyclopentane, dichloromethane, chloroform, dichloroethane, bromoethane, dibromoethane, toluene, o-xylene, and p-xylene.

In a further embodiment, the extraction solvent in S3 includes esters, carbonates, ethers, alcohols, ketones, nitriles, wherein the esters are selected from one or more combinations of methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, and vinyl acetate, the carbonates are selected from one or more combinations of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate, propylene carbonate, fluoroethylene carbonate, and ethylene difluorocarbonate, the ethers are selected from one or more combinations of diethyl ether, propyl ether, isopropyl ether, butyl ether, isobutyl ether, tetrahydrofuran, tert-butyl methyl ether, methyl tetrahydrofuran, dioxolane, dioxane, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, diethylene glycol monoethyl ether, ethylene glycol diethyl ether, propylene glycol methyl ether, and propylene glycol diethyl ether, and the alcohols are selected from one or more combinations of methanol, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol methyl ether, and propylene glycol diethyl ether, One or more combinations of ethanol, propanol, isopropanol, butanol, isobutanol, said ketones are selected from one or more combinations of acetone, butanone, methyl ethyl ketone, methyl tert-butyl ketone, pyrrolidone, and said nitriles are selected from one or more combinations of acetonitrile, propionitrile, and isopropionitrile.

In a further scheme, the vacuum degree in the S3 concentration process is 4-10 torr, the temperature is 0-50 ℃, preferably the temperature is 25-35 ℃, and the concentration is carried out to 1/6-1/3 of the volume of the original solution.

In a further embodiment, the low polar aprotic solvent in step S3 is selected from one or more of n-hexane, cyclohexane, cyclopentane, dichloromethane, chloroform, dichloroethane, bromoethane, dibromoethane, toluene, o-xylene, and p-xylene.

In a further scheme, the crystallization time in the step S3 is 12-48 hours, preferably 16-24 hours, and the crystallization temperature is-20 to-10 ℃.

In a further scheme, the vacuum degree of vacuum drying in the step S3 is 3-4 torr, the temperature is 10-50 ℃, and the preferred temperature is 20-40 ℃.

Has the advantages that:

the preparation method provided by the invention can be used for preparing high-purity lithium bis (fluorosulfonyl) imide, has high yield and stable product quality, and effectively reduces the content of impurities such as potassium ions, sodium ions, calcium ions, fluoride ions, chloride ions, sulfate ions, moisture and the like in the product.

Examples

The present invention is further described below, and the following examples are only used to more clearly illustrate the technical solutions of the present invention, but not to limit the scope of the present invention. All the following operations were carried out under anhydrous and anaerobic conditions.