阅读说明：本技术 一种利用有机金属锂试剂制备氟磺酸锂的方法 (Method for preparing lithium fluorosulfonate by using organic metal lithium reagent ) 是由 梁海波 谢文健 苏秋铭 辛伟贤 陈新滋 于 2020-06-05 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氟磺酸锂的方法,包括以下步骤:(1)以有机金属锂试剂为锂源,在低温条件与全氟己烷为溶剂下,慢慢与氟磺酸进行混合反应得到氟磺酸锂粗品。粗品采用反应溶剂洗涤5次。(2)对粗品进行减压抽干,再加入氟磺酸锂的不良有机溶剂洗涤3次,再真空抽干不良有机溶剂得固体。(3)向固体中加入碳酸酯类、腈类、醇类有机溶剂萃取,过滤,浓缩,向浓缩液中加入低极性非质子溶剂,静止结晶。(4)晶体再过滤,真空干燥便得到氟磺酸锂产品。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氟磺酸锂盐,产率高,而且产品质量稳定,还能有效降低产品中的钾离子、钠离子、钙离子、氟离子、硫酸根离子和水份等杂质含量。(The invention discloses a method for preparing lithium fluorosulfonate by using an organic metal lithium reagent, which comprises the following steps of (1) taking the organic metal lithium reagent as a lithium source, and slowly mixing and reacting with fluorosulfonic acid at a low temperature in the presence of perfluorohexane as a solvent to obtain a crude product of lithium fluorosulfonate. The crude product is washed 5 times with the reaction solvent. (2) And (3) decompressing and draining the crude product, adding a poor organic solvent of lithium fluorosulfonate, washing for 3 times, and vacuumizing the poor organic solvent to obtain a solid. (3) Adding organic solvents such as carbonate, nitrile and alcohol into the solid for extraction, filtering, concentrating, adding low-polarity aprotic solvent into the concentrated solution, and standing for crystallization. (4) And filtering the crystal again, and drying in vacuum to obtain the lithium fluorosulfonate product. 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 the lithium fluorosulfonate, has high yield and stable product quality, and can effectively reduce the content of impurities such as potassium ions, sodium ions, calcium ions, fluoride ions, sulfate ions, water and the like in the product.)

1. A method of preparing lithium fluorosulfonate using an organometallic lithium reagent, comprising the steps of:

(1) taking an organic metal lithium reagent as a lithium source, and slowly mixing and reacting with fluorosulfonic acid at a low temperature with perfluorohexane as a solvent to obtain a crude product of lithium fluorosulfonate; washing the crude product with a reaction solvent for 5 times;

(2) performing reduced pressure pumping on the crude product, adding a poor organic solvent of lithium fluorosulfonate for washing for 3 times, and performing vacuum pumping on the poor organic solvent to obtain a solid;

(3) adding organic solvents such as carbonates, nitriles and alcohols into the solid for extraction, filtering, concentrating, adding low-polarity aprotic solvents into the concentrated solution, and standing for crystallization;

(4) and filtering the crystal again, and drying in vacuum to obtain the lithium fluorosulfonate product.

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

3. The method of claim 2, wherein the alkyl lithium comprises one or more 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 of a combination of lithium ethynyl, lithium ethynyl dilithium (lithium carbide), and 1,3 dilithiopropyne.

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

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

7. The method for preparing lithium fluorosulfonate by using organometallic lithium reagent according to claim 1, wherein the molar ratio of the fluorosulfonic acid to the organometallic lithium reagent in the step (1) is 1.0: 1.0-3.0, and preferably 1.0: 1.0-1.5.

8. The method for preparing lithium fluorosulfonate by using organometallic lithium reagent as claimed in claim 1, wherein the reaction time in step (1) is 1-6 hours, preferably 2-4 hours.

9. The method for preparing lithium fluorosulfonate by using organometallic lithium reagent as claimed in claim 1, wherein the vacuum degree of the vacuum pumping-out in step (2) is 3-10 torr, preferably 4-6 torr, and the temperature is 0-60 ℃, preferably 20-40 ℃.

10. The method for preparing lithium fluorosulfonate by using organometallic lithium reagent as claimed in claim 1, wherein the poor organic solvent in step (2) is selected from one or more combinations of n-hexane, cyclohexane, cyclopentane, dichloromethane, chloroform, dichloroethane, bromoethane, dibromoethane, toluene, o-xylene, and p-xylene.

11. The method for preparing lithium fluorosulfonate using organometallic lithium reagent as claimed in claim 1, wherein the vacuum degree of the vacuum pumping in the step (2) is 3-5 torr, and the temperature is 20-40 ℃.

12. The method of claim 1, wherein the step (3) is performed by extracting one or more combinations of one or more of the solvents selected from the group consisting of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate, propylene carbonate, fluoroethylene carbonate and ethylene difluorocarbonate, nitriles are selected from one or more combinations of acetonitrile, propionitrile and isopropionitrile, and alcohols are selected from one or more combinations of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, propylene glycol methyl ether and propylene glycol ethyl ether.

13. The method for preparing lithium fluorosulfonate using organometallic lithium reagent as claimed in claim 1, wherein the concentration in step (3) is performed under a vacuum of 4to 6torr and at a temperature of 20 to 40 ℃ until the concentration is 1/6 to 1/3% of the volume of the original solution.

14. The method for preparing lithium fluorosulfonate by using organometallic lithium reagent as claimed in claim 1, wherein the low polar aprotic solvent in step (3) is selected from one or more of petroleum ether, n-hexane, cyclohexane, cyclopentane, dichloromethane, chloroform, dichloroethane, bromoethane, dibromoethane, toluene, o-xylene, and p-xylene.

15. The method for preparing lithium fluorosulfonate using organometallic lithium reagent according to claim 1, wherein the crystallization time in step (3) is 12-48 hours, preferably 16-24 hours, and the crystallization temperature is-20 to-10 ℃.

16. The method for preparing lithium fluorosulfonate by using organic metal lithium reagent as claimed in claim 1, wherein said filtering in step (4) is performed by suction filtration under reduced pressure using a sand core G4.

17. The method for preparing lithium fluorosulfonate by using organometallic lithium reagent as claimed in claim 1, wherein the vacuum drying degree in step (4) is 3-4 torr, and the temperature is 10-50 ℃, preferably 20-40 ℃.

Technical Field

The invention relates to a method for preparing lithium fluorosulfonate by using an organic metal lithium reagent, belonging to the technical field of chemical synthesis.

Background

1. Lithium fluorosulfonate abbreviated LiFSO₃And the molecular weight is 106.1. Pure lithium fluorosulfonate is a white solid. The lithium fluorosulfonate is a chemical substance which can be widely applied to the field of electronic batteries, is widely applied, and has high purity, and is suitable for being used as a non-aqueous electrolyte additive of a secondary lithium ion battery. The electrolyte has the characteristics of electrochemical stability and thermal stability in the electrolyte, can improve the cycle performance and high-temperature storage performance of a secondary lithium ion battery, can inhibit the gas generation of the electrolyte in the using process, thereby improving the overall performance of the secondary lithium ion battery, and shows that electrolyte additives (such as lithium difluorophosphate, lithium perchlorate, lithium hexafluoroarsenate and the like) which seriously pollute the environment can be replaced in some fields.

2. The following is a technical introduction to the prior art regarding lithium p-fluorosulfonate.

3. The article (j.chem.soc. (a),1967, (3),355-358) reported the preparation of lithium fluorosulfonate by a salt exchange reaction of fluorosulfonic acid with lithium acetate in an acetic acid solvent.

4. The electrical properties of lithium fluorosulfonate in EP2698350(a1) and CN 103492319B are studied intensively, and it is found that the characteristics can improve the high-temperature capacity of the secondary lithium ion battery, and the gas generation of the electrolyte can be inhibited during the use process, so as to improve the overall performance of the battery, and therefore, the synthesis of high-purity lithium fluorosulfonate will be helpful to improve the lithium ion battery technology. In the patent, it is proposed that fluorosulfonic acid reacts with various inorganic lithium as lithium sources to generate lithium fluorosulfonate, and then the lithium fluorosulfonate is obtained through post-treatment and purification, so that the product purity is high. Since these patents do not mention the preparation method using metal organic lithium reagent as lithium source, the present invention proposes a preparation method using metal organic lithium as lithium source in order to enrich the preparation route of lithium fluorosulfonate.

Disclosure of Invention

1. The invention aims to enrich the defects of lithium source of the reaction of the invention and provide another brand-new method for preparing lithium fluorosulfonate.

2. In order to enrich the problem of the lithium source, the invention adopts the technical scheme of preparing the lithium fluorosulfonate by a brand new path

Comprises the following steps:

(1) taking an organic metal lithium reagent as a lithium source, and slowly mixing and reacting with fluorosulfonic acid at a low temperature with perfluorohexane as a solvent to obtain a crude product of lithium fluorosulfonate. The crude product is washed 5 times with the reaction solvent.

(2) And (3) decompressing and draining the crude product, adding a poor organic solvent of lithium fluorosulfonate, washing for 3 times, and vacuumizing the poor organic solvent to obtain a solid.

(3) Adding organic solvents such as carbonate, nitrile and alcohol into the solid for extraction, filtering, concentrating, adding low-polarity aprotic solvent into the concentrated solution, and standing for crystallization.

(4) And filtering the crystal again, and drying in vacuum to obtain the lithium fluorosulfonate product.

3. The preparation steps are carried out under the protection of inert gas and without water.

4. The organic metal lithium reagent in the step (1) comprises alkyl lithium, alkynyl lithium and aryl lithium.

5. The alkyllithium described in summary 4 includes one or more combinations of methyllithium, ethyllithium, n-butyllithium, isobutyllithium, tert-butyllithium, 1, 5-dilithiopentane.

6. The alkynyl lithium described in summary 4 includes one or more combinations of ethynyllithium, ethynyldilithium (lithium carbide), 1, 3-dilithiopropylene.

7. The aryl lithium described in the invention 4 includes one or more of phenyl lithium, benzyl lithium, phenylethynyl lithium, 2,4, 6-trimethyl phenyl lithium and naphthalene lithium.

8. The low temperature condition in the step (1) of the technical scheme is 0 to-78 ℃. The preferred temperature is 0 to-20 ℃.

9. According to the technical scheme, the molar ratio of the fluorosulfonic acid to the organic metal lithium reagent in the step (1) is 1.0: 1.0-3.0, and the preferable ratio is 1.0: 1.0-1.5.

10. The reaction time in the step (1) of the technical scheme is 1-6 hours, and the preferable reaction time is 2-4 hours.

11. In the technical scheme, the vacuum degree of decompression and pumping in the step (2) is 3-10 torr, preferably 4-6 torr, and the temperature is 0-60 ℃. The preferred temperature is 20-40 ℃.

12. Technical scheme the halogen organic solvent in step (2) is selected from one or more of chloroform, dichloromethane, chlorobenzene, dichlorobenzene, dichloroethane, bromobenzene, dibromobenzene, bromoethane and dibromoethane.

13. Technical scheme the poor organic solvent in step (2) is selected from one or more of n-hexane, cyclohexane, cyclopentane, dichloromethane, chloroform, dichloroethane, bromoethane, dibromoethane, toluene, o-xylene and p-xylene.

14. The vacuum degree of vacuum pumping in the step (2) is 3-5 torr, and the temperature is 20-40 ℃.

15. According to the technical scheme, in the step (3), one or more combinations of one or more of solvents of carbonate dimethyl, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate, propylene carbonate, fluoroethylene carbonate and difluoroethylene carbonate are extracted, nitriles are selected from one or more combinations of acetonitrile, propionitrile and isopropionitrile, and alcohols are selected from one or more combinations of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, diethanol monoethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether and propylene glycol diethyl ether.

16. According to the technical scheme, the vacuum degree during concentration in the step (3) is 4-6 torr, and the temperature is 20-40 ℃. Concentrating to 1/6-1/3 of the volume of the original solution.

17. The low-polarity aprotic solvent in the step (3) is selected from one or more of petroleum ether, n-hexane, cyclohexane, cyclopentane, dichloromethane, chloroform, dichloroethane, bromoethane, dibromoethane, toluene, o-xylene and p-xylene.

18. The crystallization time in the step (3) of the technical scheme is 12-48 hours. The preferable time is 16 to 24 hours. The crystallization temperature is-20 to-10 ℃.

19. The filtration in the step (4) of the technical scheme adopts a G4 sand core for decompression suction filtration.

20. The vacuum drying vacuum degree in the step (4) of the technical scheme is 3-4 torr, and the temperature is 10-50 ℃. The preferred temperature is 20-40 ℃.

21. The invention achieves the following beneficial effects:

the preparation method provided by the invention can be used for preparing the lithium fluorosulfonate, has high yield and stable product quality, and can effectively reduce the content of impurities such as potassium ions, sodium ions, calcium ions, fluoride ions, sulfate ions, water and the like in the product.

Detailed Description

1. 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.

2. All the following operations were carried out under anhydrous and anaerobic conditions.

3. Example 1

A100 mL solvent storage bottle (bottle A) was transferred to 60mL (0.06mol) of a 1mol/L (ethyllithium/benzene) solution for use. Another 100mL solvent storage bottle (bottle B) was transferred with 5g (0.05mol) of fluorosulfonic acid and 50mL of perfluorohexane, and mixed thoroughly for further use. A1000 mL reaction flask was prepared, 50mL perfluorohexane and a stirrer were added to the flask, the flask was cooled to-10 ℃, and then the solutions from flask A and flask B were slowly added dropwise through a capillary tube to the 1000mL reaction flask to start the reaction. The reaction temperature was maintained at-10 ℃. The dropwise addition was completed in about 2.5 hours, after completion of the dropwise addition. The reaction was continued for 1 hour. After the reaction was complete, the stirring was stopped, the temperature was slowly returned to room temperature, whereupon a solid precipitated at the bottom of the flask and the reaction solvent was poured out into a 1000ml flask (flask D). The solid was then washed with perfluorohexane (50 mL. times.5). The washing liquid is uniformly collectedCollected in a bottle D for recycling. After washing, the residual solvent perfluorohexane was dried by vacuum pumping at 4torr reduced pressure to obtain a white solid. The solid was washed with dichloromethane (100 mL. times.3). After washing, the residual dichloromethane was then dried under a vacuum of 4 torr. So as to obtain crude lithium fluorosulfonate. Dissolving the crude product by 50mL of ultra-dry dimethyl carbonate, filtering by a PTFE filter membrane with the aperture of 0.22 mu m after full dissolution, and concentrating the obtained clear liquid by a rotary evaporator under the vacuum degree of 4torr to obtain a sticky concentrate. To the concentrate was added 100mL of toluene and crystallization was carried out at-20 ℃ for 24 hours. The crystals were obtained by filtration and removed from the vacuum oven and dried at 35 ℃ for 8 hours at 3torr vacuum. This gave 4.75g of white lithium fluorosulfonate crystals. The yield was 89.6%. And (3) detection results: ICP-OES (ppm): na (Na)⁺＝18.8ppm，K⁺＝24.1ppm，Fe²⁺＝2.6ppm，Ca²⁺＝13.4ppm；Mg²⁺＝0.13ppm；IC：F^－＝20.1ppm，Cl^－＝8.3ppm，SO₄ ^2-＝30.9ppm。KF：H₂O＝22.8ppm。¹⁹FNMR(400MHz,DMSO-d6):40.23ppm。

4. Example 2

A100 mL solvent storage bottle (bottle A) was transferred to 39.1mL (0.0625mol) of a 1.6mol/L (n-butyllithium/n-hexane) solution for future use. Another 100mL solvent storage bottle (bottle B) was transferred with 5g (0.05mol) of fluorosulfonic acid and 50mL of perfluorohexane, and mixed thoroughly for further use. A1000 mL reaction flask was prepared, 50mL perfluorohexane and a stirrer were added to the flask, the flask was cooled to-15 ℃, and then the solutions from flask A and flask B were slowly added through capillary tubes to the flask to start the reaction. The reaction temperature was maintained at-15 ℃. The dropwise addition was completed in about 3 hours, after completion of the dropwise addition. The reaction was continued for 1 hour. After the reaction was complete, the stirring was stopped, the temperature was slowly returned to room temperature, whereupon a solid precipitated on the bottom of the flask, and the reaction solvent perfluorohexane was poured out into a 1000ml flask (flask D). The solid was then washed with perfluorohexane (50 mL. times.5). The washing liquid was also collected in a bottle D for recovery. After washing, the residual solvent perfluorohexane was dried by vacuum pumping under reduced pressure of 3torr to obtain a white solid. The solid was washed with dichloromethane (60 mL. times.3). After washing, the residual is treated by 4torr vacuum degreeAnd (5) pumping the dichloromethane to dryness. So as to obtain crude lithium fluorosulfonate. Dissolving the crude product by using 50mL of ultra-dry acetonitrile, filtering by using a PTFE filter membrane with the aperture of 0.22 mu m after fully dissolving, and concentrating the obtained clear liquid by using a rotary evaporator under the vacuum degree of 4torr to obtain a viscous concentrate. To the concentrate was added 150mL of dichloromethane and crystallization was carried out at-20 ℃ for 24 hours. The crystals were obtained by filtration and removed from the vacuum oven and dried at 35 ℃ for 8 hours at 3torr vacuum. This gave 4.89g of white lithium fluorosulfonate crystals. The yield was 92.3%. And (3) detection results: ICP-OES (ppm): na (Na)⁺＝26.3ppm，K⁺＝31.1ppm，Fe²⁺＝1.6ppm，Ca²⁺＝13.2ppm；Mg²⁺＝0.78ppm；IC：F^－＝24.9ppm，Cl^－＝7.5ppm，SO₄ ^2-＝34.5ppm。KF：H₂O＝25.1ppm。¹⁹FNMR(400MHz,DMSO-d6):40.23ppm。

5. Example 3

A100 mL solvent storage bottle (bottle A) was transferred to 35.9mL (0.0575mol) of a 1.6mol/L (phenyllithium/cyclohexane) solution for use. Another 100mL solvent storage bottle (bottle B) was transferred with 5g (0.05mol) of fluorosulfonic acid and 50mL of perfluorohexane, and mixed thoroughly for further use. A1000 mL reaction flask was prepared, 50mL perfluorohexane and a stirrer were added to the flask, the flask was cooled to-20 ℃, and then the solutions in flask A and flask B were slowly added through a capillary tube to the flask to start the reaction. The reaction temperature was maintained at-20 ℃. The dropwise addition was completed for about 2 hours, after completion of the dropwise addition. The reaction was continued for 2 hours. After the reaction was complete, the stirring was stopped and the temperature was allowed to return to room temperature, whereupon a solid precipitated on the bottom of the flask and the reaction solvent cyclohexane was poured out into a 1000ml flask (flask D). The solid was then washed with perfluorohexane (30 mL. times.5). The washing liquid was also collected in a bottle D for recovery. After washing, the residual solvent perfluorohexane was dried by vacuum-pumping under reduced pressure of 3torr to obtain a white solid. The solid was washed with chloroform (60 mL. times.3). After washing, the residual chloroform was dried under a vacuum of 4 torr. So as to obtain crude lithium fluorosulfonate. Dissolving the crude product with 50mL of ultra-dry methanol, filtering with 0.22 μm-pore PTFE filter membrane, and concentrating the obtained clear solution with rotary evaporator under 4torr vacuum degree to obtain viscous solutionA thick concentrate. To the concentrate was added 150mL of dichloroethane and crystallization was carried out at-20 ℃ for 24 hours. The crystals were obtained by filtration and removed from the vacuum oven and dried at 35 ℃ for 8 hours at 3torr vacuum. This gave 4.81g of white lithium fluorosulfonate crystals. The yield was 90.8%. And (3) detection results: ICP-OES (ppm): na (Na)⁺＝21.9ppm，K⁺＝28.7ppm，Fe²⁺＝0.92ppm，Ca²⁺＝18.1ppm；Mg²⁺＝0.63ppm；IC：F^－＝26.7ppm，Cl^－＝9.1ppm，SO₄ ^2-＝32.7ppm。KF：H₂O＝20.8ppm。¹⁹FNMR(400MHz,DMSO-d6):40.22ppm。

6. Example 4

1.045g (0.0275mol) of dilithium acetylenate (lithium carbide) was charged into a 500mL reaction flask (flask A), 50mL of perfluorohexane was further added, and then cooled to-78 ℃ for use. Another 100mL solvent storage bottle (bottle B) was transferred to 5g (0.025mol) of fluorosulfonic acid and 50mL of perfluorohexane, and mixed thoroughly for further use. The solution in vial B was then slowly added dropwise to reaction vial A through a capillary. The reaction temperature was maintained at-78 ℃. The dropwise addition was completed in about 3 hours, after completion of the dropwise addition. The reaction was continued for 1 hour. After the reaction was completed, the stirring was stopped, the temperature was returned to room temperature, and the reaction solvent perfluorohexane was poured out into a 1000ml bottle (bottle D). The solid was then washed with perfluorohexane (30 mL. times.3). The washing liquid was also collected in a bottle D for recovery. After washing, the residual solvent perfluorohexane was dried by vacuum-pumping under reduced pressure of 3torr to obtain a white solid. So as to obtain crude lithium fluorosulfonate. Dissolving the crude product with 50mL of anhydrous ethylene glycol monomethyl ether, filtering with a PTFE filter membrane with a pore size of 0.22 μm after full dissolution, and concentrating the obtained clear liquid with a rotary evaporator under a vacuum degree of 4torr to obtain a viscous concentrate. To the concentrate was added 150mL of dichloromethane and crystallization was carried out at-20 ℃ for 24 hours. The crystals were obtained by filtration and removed from the vacuum oven and dried at 30 ℃ for 8 hours under a vacuum of 4 torr. This gave 4.85g of white lithium fluorosulfonate crystals. The yield was 91.5%. And (3) detection results: ICP-OES (ppm): na (Na)⁺＝17.5ppm，K⁺＝13.6ppm，Fe²⁺＝0.53ppm，Ca²⁺＝3.79ppm；Mg²⁺＝0.85ppm；IC：F^－＝29.8ppm，Cl^－＝16.4ppm，SO₄ ^2-＝26.8ppm。KF：H₂O＝21.2ppm。¹⁹FNMR(400MHz,DMSO-d6):40.23ppm。

7. The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.