Nitrogen-containing heterocyclic compounds, methods of making, and uses thereof

Abstract

The application provides a nitrogen-containing heterocyclic compound, a preparation method and application thereof. The structural formula of the nitrogen-containing heterocyclic compound is shown as formula I, wherein R1 is SO2F or CH2-(CH2) n -SO2F, R2 and R3 are each independently M, SO2F or CH2-(CH2) n -SO2F, n is an integer of 1-10, and M is hydrogen or an alkali metal. In the nitrogen-containing heterocyclic compound, the active hydrogen protons on the acetaldehyde ammonia trimer are partially or totally replaced, so that the negative influence of the active hydrogen protons on the performance of a battery can be weakened. The ring heteroatom and N-S bond structure of the nitrogen-containing heterocyclic compound can efficiently complex metal ions, so that the nitrogen-containing heterocyclic compound can be used as an electrolyte additive, thereby solving the problem of dissolution of metal ions in a positive electrode of the battery. The active hydrogen protons are partially or totally replaced by a sulfonyl fluoride or alkyl sulfonyl fluoride functional group, and the sulfonyl fluoride group can improve the ionic conductivity and thermal stability of the nitrogen-containing heterocyclic compound, thereby improving the rate performance and high-temperature performance of the battery.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of material synthesis, in particular to a compound applied to a battery, and more particularly to a nitrogen-containing heterocyclic compound, a preparation method and an application thereof. BACKGROUND

[0002] In energy storage devices such as lithium ion batteries and sodium ion batteries, the performance of the positive electrode material directly affects the overall performance of the battery. However, during the charging and discharging process of the battery, especially under high temperature and high voltage conditions, transition metal ions at the interface of the positive electrode material can partially dissolve into the electrolyte. For example, elements such as nickel (Ni), cobalt (Co), manganese (Mn), and iron (Fe) in lithium ion batteries, and elements such as chromium (Cr), iron (Fe), and nickel (Ni) in sodium ion batteries, can be dissolved under certain conditions. The dissolution of metal ions has a negative impact on the capacity, cycle life, and self-discharge of the battery. For example, dissolved transition metal ions such as Ni and Mn can be corroded by HF, destroying the material structure stability and leading to rapid degradation of the battery cycle performance. In addition, these dissolved metal ions can also cause electrolyte decomposition, forming a surface film with high impedance and instability, further reducing the coulombic efficiency and cycle performance of the battery.

[0003] In addition, trithiocyanic acid is a good heavy metal ion removal agent. The sodium salt hydrate (TMT-3Na9H2O) of trithiocyanic acid was first reported in US4849517A. Through the formation of stable complex precipitates between trithiocyanate anions and metal ions such as Ni + , Pb 2+ , Cu 2+ , Ag + , Zn 2+ , Cd 2+ , Hg 2+ in solution, the purpose of removing heavy metal ions can be achieved.

[0004] Acetaldehyde ammonia trimer has a similar functional skeleton to trithiocyanic acid. Adding acetaldehyde ammonia trimer to the electrolyte to regulate the electrolyte composition can inhibit the dissolution of metal ions. However, due to the presence of numerous active hydrogen protons in acetaldehyde ammonia trimer, if acetaldehyde ammonia trimer is used in batteries, the active hydrogen protons may react with lithium hexafluorophosphate or other components in the electrolyte, affecting the first charge and discharge capacity, internal resistance, cycle life, and volume of the battery. Therefore, there are few reports on the use of acetaldehyde ammonia trimer in battery systems. SUMMARY

[0005] Based on the above problems, the purpose of the present application is to provide a nitrogen-containing heterocyclic compound, a preparation method and an application thereof, which modifies acetaldehyde ammonia trimer, and weakens the influence of active hydrogen protons on battery performance by partially or completely replacing the active hydrogen protons. In addition, the performance of the battery can be further improved by introducing a sulfonyl fluoride or alkyl sulfonyl fluoride functional group.

[0006] To achieve the above-mentioned purpose, the first aspect of the present application provides a nitrogen-containing heterocyclic compound, the structural formula of which is shown as formula I, wherein R1 is SO2F or CH2-(CH2) n -SO2F, R2 and R3 are each independently M, SO2F or CH2-(CH2) n -SO2F, n is an integer of 1-10, and M is hydrogen or an alkali metal.

[0007] Formula I

[0008] The nitrogen-containing heterocyclic compound of the present application is a compound shown as formula I, which partially or completely replaces the active hydrogen protons on acetaldehyde ammonia trimer, and can weaken the negative influence of active hydrogen protons on battery performance. The ring hybridization and N-S bond structure of the nitrogen-containing heterocyclic compound can efficiently complex metal ions, so the nitrogen-containing heterocyclic compound can be used as an electrolyte additive, thereby solving the problem of metal ion dissolution in the positive electrode of the battery and improving the cycle performance of the battery. In addition, the active hydrogen protons in the nitrogen-containing heterocyclic compound of the present application are partially or completely replaced by a sulfonyl fluoride or alkyl sulfonyl fluoride functional group, and the sulfonyl fluoride group can improve the ionic conductivity and thermal stability of the nitrogen-containing heterocyclic compound, and can improve the rate performance and high-temperature performance of the battery when used in the battery.

[0009] As a technical solution of the present application, n is an integer of 1-2, and M is hydrogen or lithium.

[0010] As a technical solution of the present application, the nitrogen-containing heterocyclic compound is at least one of compound one to compound five.

[0011]

[0012] Compound one Compound two Compound three

[0013]

[0014] Compound four Compound five

[0015] The second aspect of the present application provides a preparation method of a nitrogen-containing heterocyclic compound, comprising the steps of:

[0016] (1) mixing acetaldehyde ammonia trimer and a first medium at a certain temperature to form a first solution;

[0017] (2) adding sulfuryl fluoride or alkenyl sulfonyl fluoride to the first solution to react to obtain a product, and purifying the product, wherein the alkenyl sulfonyl fluoride has a structure of CH2=CH-(CH2) n-1 -SO2F, and n is an integer from 1 to 10.

[0018] The preparation method of the present application synthesizes a series of nitrogen-containing heterocyclic compounds with weakened active hydrogen protons by modifying acetaldehyde ammonia trimer with sulfuryl fluoride or alkenyl sulfonyl fluoride. The nitrogen-containing heterocyclic compounds prepared have both sulfuryl fluoride groups and intramolecular heterostructure, which can greatly improve the cycle, rate and high-temperature performance of the battery. The preparation method of the nitrogen-containing heterocyclic compounds has the advantages of easy preparation of raw materials, simple operation, high yield, mild conditions, low requirement for equipment and suitability for large-scale industrial production.

[0019] As a technical solution of the present application, the first medium is a first solvent or a combination of a first solvent and an organic base.

[0020] As a technical solution of the present application, the first solvent includes at least one of an alcohol solvent, a nitrile solvent, a halogenated hydrocarbon solvent, an ether solvent, an ester solvent and a ketone solvent, and the organic base includes at least one of triethylamine, pyridine, 1,8-diazabicycloundec-7-ene and tetramethylpropylenediamine.

[0021] As a technical solution of the present application, the purification treatment includes mode ①: pre-treatment after rough treatment, and the pre-treatment includes cooling crystallization or chromatographic column separation.

[0022] As a technical solution of the present application, the purification treatment includes mode ②: dissolution with a second solvent after evaporation and rotary drying, and then washing, dehydrating, filtering and concentrating the organic phase.

[0023] As a technical solution of the present application, the purification treatment includes mode ③: quenching reaction after evaporation and rotary drying, dissolution with a second solvent, and then washing, dehydrating, filtering and concentrating the organic phase.

[0024] As a technical solution of the present application, the molar ratio of the acetaldehyde ammonia trimer to the sulfuryl fluoride is 1:1.0-3.2, or the molar ratio of the acetaldehyde ammonia trimer to the alkenyl sulfonyl fluoride is 1:1.0-3.2, the temperature is -20-40℃, and the holding time is 2-3h.

[0025] The present application provides a preparation method of an alkali metal salt of a nitrogen-containing heterocyclic compound, which comprises the following steps:

[0026] (1) mixing acetaldehyde ammonia trimer and a first medium at a certain temperature to form a first solution;

[0027] (ii) adding sulfuric fluoride or alkenyl sulfuryl fluoride, CH2=CH-(CH2) n-1 -SO2F, n is an integer from 1 to 10, and the molar ratio of the acetaldehyde ammonia trimer to the sulfuric fluoride is 1:2.0-2.2 or the molar ratio of the acetaldehyde ammonia trimer to the alkenyl sulfuryl fluoride is 1:2.0-2.2,

[0028] (iii) mixing the first product with a third solvent to form a second solution, and adding a base metal compound to the second solution and adjusting the pH value to react,

[0029] and purifying the reactant.

[0030] In the preparation method of the nitrogen-containing heterocyclic compound base metal salt, the acetaldehyde ammonia trimer is first modified by sulfuric fluoride or alkenyl sulfuryl fluoride to partially replace the active hydrogen protons to obtain a nitrogen-containing heterocyclic compound, and then the remaining active hydrogen protons are replaced by a base metal compound to obtain a nitrogen-containing heterocyclic compound base metal salt. In the preparation method, not only the active hydrogen protons can be completely replaced, but also the sulfuric fluoride group can be introduced, and the prepared nitrogen-containing heterocyclic compound base metal salt can greatly improve the performance of the battery.

[0031] The fourth aspect of the present application provides the use of the aforementioned nitrogen-containing heterocyclic compound, the nitrogen-containing heterocyclic compound prepared by the aforementioned preparation method of the nitrogen-containing heterocyclic compound, or the nitrogen-containing heterocyclic compound base metal salt prepared by the aforementioned preparation method of the nitrogen-containing heterocyclic compound base metal salt as an electrolyte additive. DETAILED DESCRIPTION

[0032] The structural formula of the nitrogen-containing heterocyclic compound of the present application is shown as formula I, wherein R1 is SO2F or CH2-(CH2) n -SO2F, R2 and R3 are each independently M, SO2F or CH2-(CH2) n -SO2F, n is an integer from 1 to 10, and M is hydrogen or a base metal. The base metal can be lithium, sodium, potassium, rubidium or cesium, preferably lithium or sodium. n can be but is not limited to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. Further, n is an integer from 1 to 2, and M is hydrogen or lithium. The nitrogen-containing heterocyclic compound can be a nitrogen-containing heterocyclic compound or a nitrogen-containing heterocyclic compound base metal salt. Specifically, when M is hydrogen, R2 and R3 are each independently hydrogen, SO2F or CH2-(CH2) n -SO2F, which is a nitrogen-containing heterocyclic compound. When M is a base metal, R2 and R3 are each independently a base metal, SO2F or CH2-(CH2) n -SO2F, and at least one of R2 and R3 is a base metal, which is a nitrogen-containing heterocyclic compound base metal salt.

[0033]

[0034] Formula I

[0035] Preferably, the nitrogen-containing heterocyclic compound can be at least one of Compound One to Compound Five. Among them, Compound One to Compound Four are nitrogen-containing heterocyclic compounds, and Compound Five is a nitrogen-containing heterocyclic compound alkali metal salt.

[0036]

[0037] Compound One Compound Two Compound Three

[0038]

[0039] Compound Four Compound Five

[0040] The nitrogen-containing heterocyclic compound of the present application can be used as an intermediate to synthesize various adjuvants, and can also be used as an electrolyte additive. The use of the nitrogen-containing heterocyclic compound as an electrolyte additive in a lithium ion battery can improve the electrochemical performance of the lithium ion battery, such as cycle, rate, and high temperature.

[0041] The lithium ion battery includes a positive electrode active material, a negative electrode active material, and an electrolyte. The positive electrode active material can be a layered transition metal lithium oxide or an olivine-type lithium compound. The layered transition metal lithium oxide can be, but is not limited to, a lithium cobalt oxide (such as LiCoO2), a lithium nickel oxide (such as LiNiO2), a lithium manganese oxide (such as LiMnO2, LiMn2O4), a lithium nickel cobalt oxide, a lithium manganese cobalt oxide, a lithium nickel manganese oxide, a lithium nickel cobalt manganese oxide (chemical formula LiNi x Co y Mn (1-x-y) M z O2, wherein 0.6≤x<0.9, x+y<1, 0≤z<0.08, M is at least one of Al, Mg, Zr, and Ti), and a coating and a dopant of the above-mentioned materials. It is especially suitable for lithium nickel cobalt manganese oxide ternary materials. These positive electrode active materials can be used alone or in combination with two or more.

[0042] The negative electrode active material includes at least one of a carbon-based material, a silicon-based material, and a tin-based material. Among them, the carbon-based material can be, but is not limited to, at least one of artificial graphite, natural graphite, hard carbon, soft carbon, graphene, and mesocarbon microbeads. The silicon-based material can be, but is not limited to, at least one of silicon single substance, silicon-oxygen composite material, silicon-carbon composite material, and silicon alloy material. The tin-based material can include tin single substance, tin-carbon composite material, tin-oxygen composite material, and tin alloy compound.

[0043] The electrolyte includes an electrolyte salt, a non-aqueous organic solvent, and an additive.

[0044] The electrolyte salt can be, but is not limited to, at least one of lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), lithium bisfluorosulfonylimide (LiFSI), lithium bis-trifluoromethylsulfonylimide (LiTFSI), lithium methylsulfonate (LiCH3SO3), lithium trifluoromethylsulfonate (LiCF3SO3), lithium bis(oxalato)borate (C4BLiO8), lithium difluoro(oxalato)borate (C2BF2LiO4), lithium difluorophosphate (LiPO2F2), and lithium difluorobis(oxalato)phosphate (LiDFBP). The non-aqueous organic solvent is selected from at least one of carbonates and / or carboxylates. Further, the non-aqueous organic solvent is selected from at least one of vinyl carbonate (PC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), γ-butyrolactone, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethyl propionate, propyl propionate, and butyl propionate.

[0045] The additive can include at least a nitrogen-containing heterocyclic compound. The nitrogen-containing heterocyclic compound has a structural formula as shown in Formula I. The nitrogen-containing heterocyclic compound accounts for 1.0-10.0% of the mass of the electrolyte. As an example, the nitrogen-containing heterocyclic compound can account for, but is not limited to, 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, 6.0%, 7.0%, 8.0%, 9.0%, or 10.0%.

[0046] The method for preparing the nitrogen-containing heterocyclic compound of the present application can include the following steps.

[0047] (1) Mixing acetaldehyde-ammonia trimer and a first medium at a certain temperature to form a first solution.

[0048] (2) Adding sulfonyl fluoride or alkenyl sulfonyl fluoride to the first solution to obtain a product, and purifying the product, wherein the alkenyl sulfonyl fluoride has a structural formula of CH2=CH-(CH2)n-SO2F, and n is an integer from 1 to 10. n-1

[0049] ​In step (1), the first medium is a first solvent or a combination of the first solvent and an organic base. If the first medium is the first solvent, the acetaldehyde-ammonia trimer and the first solvent are mixed at a temperature to form a first solution. If the first medium is the combination of the first solvent and the organic base, the acetaldehyde-ammonia trimer, the organic base and the first solvent are mixed uniformly at a temperature to form a first solution. The further addition of the organic base can neutralize the leaving group and promote the progress of the electrophilic reaction in step (2). The boiling point of the first solvent is less than 100°C, i.e., the first solvent is a low boiling point solvent. Specifically, the first solvent includes at least one of an alcohol solvent, a nitrile solvent, a halogenated hydrocarbon solvent, an ether solvent, an ester solvent and a ketone solvent. More specifically, the alcohol solvent is methanol, ethanol or isopropanol. The nitrile solvent is acetonitrile or butyronitrile. The halogenated hydrocarbon solvent is dichloromethane, trichloromethane, 1,2-dichloroethane or tetrachloroethane. The ether solvent is methyl tert-butyl ether, ethylene glycol dimethyl ether, tetrahydrofuran or dioxane, and the ester is dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, methyl acetate, ethyl acetate or propyl acetate. The ketone solvent is acetone, cyclohexanone or 4-methyl-2-pentanone. Preferably, the first solvent is acetonitrile, ethanol or dichloromethane. The organic base includes at least one of triethylamine, pyridine, 1,8-diazabicycloundec-7-ene (DBU) and tetramethylpropylenediamine (TMPDA).

[0050] In step (1), the temperature is -20-40°C, and as an example, the temperature can be but is not limited to -20°C, -15°C, -10°C, -5°C, 0°C, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C or 40°C. The incubation time is 2-3h, and as an example, can be but is not limited to 2h or 3h.

[0051] In step (2), the molar ratio of the acetaldehyde-ammonia trimer to the sulfuryl fluoride is 1:1-3.2. Specifically, when the molar ratio of the acetaldehyde-ammonia trimer to the sulfuryl fluoride is close to 1:1, only R1 in formula I is SO2F. When the molar ratio of the acetaldehyde-ammonia trimer to the sulfuryl fluoride is close to 1:2, R1 in formula I is SO2F and one of R2 and R3 is SO2F. When the molar ratio of the acetaldehyde-ammonia trimer to the sulfuryl fluoride is close to 1:3, R1, R2 and R3 in formula I are all SO2F. The molar ratio of the acetaldehyde-ammonia trimer to the alkenyl sulfonyl fluoride is 1:1-3.2. Specifically, when the molar ratio of the acetaldehyde-ammonia trimer to the alkenyl sulfonyl fluoride is close to 1:1, only R1 in formula I is CH2-(CH2) n -SO2F. When the molar ratio of the acetaldehyde-ammonia trimer to the alkenyl sulfonyl fluoride is close to 1:2, R1 in formula I is CH2-(CH2) n -SO2F, and one of R2 and R3 is CH2-(CH2) n-SO2F. The molar ratio of acetaldehyde ammonia trimer to alkenyl sulfonyl fluoride is close to 1:3, R1, R2, R3 in formula I are all CH2-(CH2) n -SO2F.

[0052] The reaction of acetaldehyde ammonia trimer and sulfonyl fluoride, or the reaction of acetaldehyde ammonia trimer and alkenyl sulfonyl fluoride can be monitored by LC / MS or GC / MS to determine the end point of the reaction, and the reaction is stopped after detecting no raw material peak after a certain time. The reaction time is 2-3 h, and the reaction temperature is 0-40℃. The lower reaction temperature can effectively reduce energy consumption. Further, the reaction time can be but not limited to 2 h, 3 h, and the reaction temperature can be but not limited to 0℃, 5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, 40℃. Sulfonyl fluoride is a gas, and the reaction condition of acetaldehyde ammonia trimer and sulfonyl fluoride is a gas-liquid reaction under high pressure, and the reaction device is preferably a high-pressure reaction kettle. In operation, the pressure in the high-pressure reaction kettle (≤0.5 MPa) can be controlled to control the feeding rate of sulfonyl fluoride gas. Alkenyl sulfonyl fluoride is a liquid, and the reaction device of acetaldehyde ammonia trimer and alkenyl sulfonyl fluoride is preferably a three-necked flask.

[0053] The product obtained after the reaction of acetaldehyde ammonia trimer and sulfonyl fluoride, or the reaction of acetaldehyde ammonia trimer and alkenyl sulfonyl fluoride can be further purified and treated. The purification and treatment can be in the following various ways.

[0054] Method ①: After crude treatment, pre-treatment is performed, which includes cooling crystallization or chromatographic column separation, and vacuum drying after pre-treatment. The crystallization temperature of cooling crystallization is -20-10℃, and the cooling crystallization time is 1-5 h. The vacuum drying temperature is 80-150℃, and the drying time is 8-30 h.

[0055] Method ②: After evaporation and rotary drying, a second solvent is used for dissolution, and then the organic phase is washed, dehydrated, filtered, and concentrated. The second solvent is an ester solvent, a halogenated hydrocarbon solvent, or an ether solvent. More specifically, the ester solvent is dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, methyl acetate, ethyl acetate, or propyl acetate. The halogenated hydrocarbon solvent is dichloromethane, trichloromethane, 1,2-dichloroethane, or tetrachloroethane. The ether solvent is diethyl ether, methyl tert-butyl ether, ethylene glycol dimethyl ether, tetrahydrofuran, or dioxane. Preferably, the second solvent is ethyl acetate, dichloromethane, or dichloroethane. Specifically, the organic phase is washed with salt water in turn, and dehydrated and dried with anhydrous magnesium sulfate.

[0056] Method ③: After evaporation and rotary drying, the reaction is quenched, a second solvent is used for dissolution, and then the organic phase is washed, dehydrated, filtered, and concentrated. Deionized water or ice water can be used for quenching reaction.

[0057] The nitrogen-containing heterocyclic compound of the present application can be further realkalized to prepare an alkali metal salt of the nitrogen-containing heterocyclic compound, and the method for preparing the same comprises the following steps.

[0058] (I) mixing the acetaldehyde-ammonia trimer and a first medium at a certain temperature to form a first solution.

[0059] (II) adding sulfuryl fluoride or alkenyl sulfonyl fluoride to the first solution to obtain a first product, wherein the structure of the alkenyl sulfonyl fluoride is CH2=CH-(CH2) n-1 -SO2F, and n is an integer from 1 to 10.

[0060] (III) mixing the first product with a third solvent to form a second solution, adding an alkali metal compound to the second solution and adjusting the pH value to react, and purifying the reaction product.

[0061] In step (I), the first medium is a first solvent or a combination of the first solvent and an organic base. If the first medium is the first solvent, the acetaldehyde-ammonia trimer and the first solvent are mixed at a certain temperature to form a first solution. If the first medium is a combination of the first solvent and an organic base, the acetaldehyde-ammonia trimer, the organic base and the first solvent are mixed uniformly, and then mixed at a certain temperature to form a first solution. Further addition of the organic base can neutralize the leaving group and promote the progress of the electrophilic reaction in step (II). The boiling point of the first solvent is less than 100°C, i.e. the first solvent is a low-boiling-point solvent. Specifically, the first solvent includes at least one of an alcohol solvent, a nitrile solvent, a halogenated hydrocarbon solvent, an ether solvent, an ester solvent and a ketone solvent. More specifically, the alcohol solvent is methanol, ethanol or isopropanol. The nitrile solvent is acetonitrile or butyronitrile. The halogenated hydrocarbon solvent is dichloromethane, trichloromethane, 1,2-dichloroethane or tetrachloroethane. The ether solvent is methyl tert-butyl ether, ethylene glycol dimethyl ether, tetrahydrofuran or dioxane. The ester is dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, methyl acetate, ethyl acetate or propyl acetate. The ketone solvent is acetone, cyclohexanone or 4-methyl-2-pentanone. Preferably, the first solvent is acetonitrile, ethanol or dichloromethane. The organic base includes at least one of triethylamine, pyridine, 1,8-diazabicycloundec-7-ene (DBU) and tetramethylpropylenediamine (TMPDA). The certain temperature is -20 to 40°C, and as an example, the temperature can be but is not limited to -20°C, -15°C, -10°C, -5°C, 0°C, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C or 40°C. The holding time is 2 to 3 hours, and as an example, can be but is not limited to 2 hours or 3 hours.

[0062] In step (ii), in order to react the remaining active hydrogen protons with sulfuryl fluoride, the molar ratio of acetaldehyde ammonia trimer to sulfuryl fluoride is 1:2.0-2.2. Specifically, when the molar ratio of acetaldehyde ammonia trimer to sulfuryl fluoride is close to 1:1, only R1 in formula I is SO2F, and there are two active hydrogen protons remaining in the first product, which are subsequently replaced by alkali metals in whole or in part. When the molar ratio of acetaldehyde ammonia trimer to sulfuryl fluoride is close to 1:2, R1 in formula I is SO2F, and one of R2 and R3 is SO2F and the other is an active hydrogen proton, indicating that there is one active hydrogen proton remaining in the first product, which is subsequently replaced by alkali metals in whole or in part. The molar ratio of acetaldehyde ammonia trimer to alkenyl sulfonyl fluoride is 1:2.0-2.2. Specifically, when the molar ratio of acetaldehyde ammonia trimer to alkenyl sulfonyl fluoride is close to 1:1, only R1 in formula I is CH2-(CH2) n -SO2F, and there are two active hydrogen protons remaining in the first product, which are subsequently replaced by alkali metals in whole or in part. When the molar ratio of acetaldehyde ammonia trimer to alkenyl sulfonyl fluoride is close to 1:2, R1 in formula I is CH2-(CH2) n -SO2F, and one of R2 and R3 is CH2-(CH2) n -SO2F and the other is an active hydrogen proton, indicating that there is one active hydrogen proton remaining in the first product, which is subsequently replaced by alkali metals in whole or in part. The reaction of acetaldehyde ammonia trimer with sulfuryl fluoride or acetaldehyde ammonia trimer with alkenyl sulfonyl fluoride can be monitored by LC / MS or GC / MS to determine the end point of the reaction, and the reaction is stopped after a certain period of time when no peak of the raw material is detected. The reaction time is 2-3 h, and the reaction temperature is 0-40°C. A lower reaction temperature can effectively reduce energy consumption. Further, the reaction time can be, but is not limited to, 2 h, 3 h, and the reaction temperature can be, but is not limited to, 0°C, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, or 40°C. Sulfuryl fluoride is a gas, and the reaction conditions of acetaldehyde ammonia trimer with sulfuryl fluoride are gas-liquid reaction under high pressure. The reaction device is preferably a high-pressure reaction kettle, and the rate of sulfuryl fluoride gas can be controlled by controlling the pressure (≤0.5 MPa) in the high-pressure reaction kettle. Alkenyl sulfonyl fluoride is a liquid, and the reaction device of acetaldehyde ammonia trimer with alkenyl sulfonyl fluoride is preferably a three-necked flask.

[0063] The product obtained after the reaction of acetaldehyde ammonia trimer with sulfuryl fluoride or acetaldehyde ammonia trimer with alkenyl sulfonyl fluoride can be directly subjected to step (iii) to obtain the alkali metal salt of the nitrogen-containing heterocyclic compound, or can be purified first to obtain the alkali metal salt of the nitrogen-containing heterocyclic compound and then subjected to the alkalization.

[0064] The purification treatment can be performed in various ways.

[0065] Method ①: After rough treatment, pre-treatment is performed, which includes temperature reduction crystallization or chromatographic column separation, and vacuum drying is performed after pre-treatment. The temperature reduction crystallization temperature is -20~10℃, and the temperature reduction crystallization time is 1~5h. The vacuum drying temperature is 80~150℃, and the drying time is 8~30h.

[0066] Method ②: After evaporation and rotary drying, the second solvent is used for dissolution, and the organic phase is taken for washing, dehydration, filtration and concentration. The second solvent is an ester solvent, a halogenated hydrocarbon solvent or an ether solvent. More specifically, the ester solvent is dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, methyl acetate, ethyl acetate or propyl acetate. The halogenated hydrocarbon solvent is dichloromethane, trichloromethane, 1,2-dichloroethane or tetrachloroethane. The ether solvent is diethyl ether, methyl tert-butyl ether, ethylene glycol dimethyl ether, tetrahydrofuran or dioxane. Preferably, the second solvent is ethyl acetate, dichloromethane or dichloroethane. Specifically, the organic phase is sequentially washed with brine, dehydrated and dried with anhydrous magnesium sulfate.

[0067] Method ③: After evaporation and rotary drying, quenching reaction is performed, the second solvent is used for dissolution, and the organic phase is taken for washing, dehydration, filtration and concentration. The quenching reaction can be operated with deionized water or ice water.

[0068] In step (three), the third solvent is at least one of an alcohol solvent, a nitrile solvent, an aqueous solvent, an ester solvent and a ketone solvent. Specifically, the alcohol solvent is methanol, ethanol or isopropanol. The nitrile solvent is acetonitrile or butyronitrile. The ester solvent is dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, methyl acetate, ethyl acetate or propyl acetate. The ketone solvent is acetone, cyclohexanone or 4-methyl-2-pentanone. Preferably, the third solvent is methanol, water or ethanol.

[0069] The alkali metal compound is a lithium compound, a sodium compound, a potassium compound, a rubidium compound or a cesium compound. Specifically, the lithium compound is lithium hydroxide, lithium hydroxide monohydrate, lithium carbonate, lithium methoxide, lithium ethoxide or lithium tert-butoxide. The sodium compound is sodium hydroxide, sodium carbonate, sodium bicarbonate, sodium methoxide, sodium ethoxide or sodium tert-butoxide. The potassium compound is potassium hydroxide, potassium carbonate, potassium bicarbonate, potassium methoxide or potassium tert-butoxide. The rubidium compound is rubidium hydroxide or rubidium carbonate. The cesium compound is cesium hydroxide, cesium hydroxide monohydrate, cesium carbonate or cesium bicarbonate. Preferably, the lithium compound is lithium hydroxide or lithium hydroxide monohydrate, the sodium compound is sodium hydroxide or sodium carbonate, the potassium compound is potassium hydroxide or potassium carbonate, the rubidium compound is rubidium hydroxide, and the cesium compound is cesium hydroxide or cesium hydroxide monohydrate.

[0070] The pH value of the first product in the alkalization reaction with the alkali metal compound is 7-8. The temperature of the reaction is 40-60°C, and as an example, the temperature can be but is not limited to 40°C, 45°C, 50°C, 55°C, or 60°C. The reaction time is 1-5h, and as an example, the time can be but is not limited to 1h, 2h, 3h, 4h, or 5h. The purification treatment can include concentration, cooling crystallization, filtration, and drying in sequence. Specifically, the temperature of the cooling crystallization is -20-10°C, the time of the cooling crystallization is 1-5h, the temperature of the drying is 80-150°C, and the time of the drying is 8-30h.

[0071] To better illustrate the purposes, technical solutions, and beneficial effects of the present application, the present application will be further described below in combination with specific examples. It should be noted that the following implementation of the method is a further explanation and description of the present application, and should not be regarded as a limitation of the present application. If the specific conditions are not specified in the examples and comparative examples, the conventional conditions or the conditions recommended by the manufacturer can be used, and the reagents or instruments not specified by the manufacturer are all conventional products that can be obtained by market purchase. The stainless steel high-pressure reaction kettle or three-necked flask used in the examples can use existing devices. For example, the stainless steel high-pressure reaction kettle can be provided with a speed-regulated stirrer, an electric heater, a cooling coil, a temperature and pressure display instrument, and at the same time, the high-pressure reaction kettle gas inlet is connected to the sulfuric fluoride steel cylinder through a stainless steel pipe connection, and the sulfuric fluoride inlet rate and amount can be controlled through a gas flow meter and an electronic balance. The three-necked flask can be provided with a speed-regulated stirrer, a constant-pressure funnel, and an acid gas absorber.

[0072] First part: preparation of nitrogen-containing heterocyclic compounds

[0073] Example 1

[0074] This example is to prepare a nitrogen-containing heterocyclic compound, and the preparation method comprises the following steps.

[0075] (1) 20g (0.155mol) of acetaldehyde ammonia trimer, 18.7g (0.185mol) of triethylamine, and 120mL of acetonitrile were loaded into a 500mL stainless steel high-pressure reaction kettle, the reaction kettle jacket temperature was set to 0°C, the cooling coil was passed through -10°C condensate water, and uniform stirring was performed for 10min to obtain a first solution.

[0076] (2) 15.8 g (0.155 mol) of sulfuryl fluoride gas was introduced to react, the reaction pressure was 0.5 MPa, the reaction time was 2.6 h, after the reaction was completed, the intermediate was obtained by evaporation and rotary evaporation, the intermediate was dissolved with ethyl acetate, the organic phase was obtained by filtration, the organic phase was washed with 100 mL of 5 wt.% sodium chloride aqueous solution for 3 times, dried with 8 g of anhydrous magnesium sulfate, filtered, and concentrated to obtain a crude product. The crude product was crystallized at -10 °C for 3 h, filtered, and vacuum dried at 120 °C for 12 h to obtain 30.1 g of compound one, and the yield of compound one was 92%.

[0077] 1H NMR (400 MHz, deuterated DMSO, ppm) of compound one: δ 1.07 (s, J = 5.8 Hz, 2H), 1.13-1.17 (d, J = 3.2 Hz, 9H), 3.85-3.88 (dd, J = 5.6 Hz, 3H).

[0078] 13C{1H} NMR (100 MHz, deuterated DMSO, ppm) of compound one: δ 18.9, 22.8, 63.5, 69.8.

[0079] The reaction equation for preparing compound one in this embodiment is as follows:

[0080]

[0081] Example 2

[0082] This embodiment is to prepare a nitrogen-containing heterocyclic compound, and the preparation method comprises the following steps.

[0083] (1) 20 g (0.155 mol) of acetaldehyde ammonia trimer, 50.2 g (0.496 mol) of triethylamine, and 160 mL of acetonitrile were charged into a 500 mL stainless steel high-pressure reaction kettle, the jacket temperature of the reaction kettle was set to 0 °C, the cooling coil was passed through -10 °C condensate water, and uniform stirring was performed for 10 min to obtain a first solution.

[0084] (2) 47.4 g (0.465 mol) of sulfuryl fluoride gas was introduced to react, the reaction pressure was 0.5 MPa, the reaction time was 2.2 h, after the reaction was completed, the intermediate was obtained by evaporation and rotary evaporation, the intermediate was dissolved with ethyl acetate, the organic phase was obtained by filtration, the organic phase was washed with 100 mL of 5 wt.% sodium chloride aqueous solution for 3 times, dried with 8 g of anhydrous magnesium sulfate, filtered, and concentrated to obtain a crude product. The crude product was separated by a chromatographic column (EA / PE = 3:7) to obtain a wet product, and the wet product was vacuum dried at 80 °C for 24 h to obtain 49.5 g of compound two, and the yield of compound two was 85%.

[0085] 1H NMR (400MHz, deuterated DMSO, ppm) of compound two: δ 1.17-1.21 (d, J = 3.4 Hz, 9H), 3.81-3.4 (dd, J = 5.8 Hz, 3H).

[0086] 13C{1H} NMR (100MHz, deuterated DMSO, ppm) of compound two: δ 15.0, 57.8.

[0087] The reaction equation for preparing compound two in this example is as follows:

[0088]

[0089] Example 3

[0090] This example is to prepare a nitrogen-containing heterocyclic compound, and the preparation method comprises the following steps.

[0091] (1) 20 g (0.155 mol) of acetaldehyde ammonia trimer and 120 mL of anhydrous ethanol were placed in a 500 mL three-necked flask, the three-necked flask was placed in an ice water bath, and the temperature of the ice water bath was controlled at 0°C, and uniform stirring was carried out for 20 min to obtain a first solution.

[0092] (2) 17.1 g (0.155 mol) of vinyl sulfonyl fluoride (the structural formula is CH2=CH-SO2F) was added for reaction, the reaction time was 2.4 h, after the reaction was completed, the first intermediate was obtained by evaporation and rotary drying, ice water was added to the first intermediate for quenching reaction to obtain a second intermediate, the second intermediate was dissolved with ethyl acetate, the organic phase was filtered, the organic phase was washed with 100 mL of 5 wt.% sodium chloride aqueous solution for 3 times, dried with 8 g of anhydrous magnesium sulfate, filtered, and concentrated to obtain a crude product. The crude product was cooled at -10°C for 3.2 h, filtered, and vacuum dried at 100°C for 12 h to obtain 33.4 g of compound three, and the yield of compound three was 90%.

[0093] 1H NMR (400MHz, deuterated DMSO, ppm) of compound three: δ 1.07 (s, J = 5.8 Hz, 2H), 1.14-1.18 (d, J = 3.2 Hz, 9H), 2.90-2.94 (t, J = 3.6 Hz, 2H), 3.49-3.52 (t, J = 3.6 Hz, 2H), 3.85-3.88 (dd, J = 5.6 Hz, 3H).

[0094] 13C{1H} NMR (100MHz, deuterated DMSO, ppm) of compound three: δ 20.6, 22.8, 40.3, 58.9, 70.1, 76.2.

[0095] The reaction equation for preparing compound three in this embodiment is as follows:

[0096]

[0097] Example 4

[0098] This embodiment is to prepare a nitrogen-containing heterocyclic compound, and the preparation method comprises the following steps.

[0099] (1) 20 g (0.155 mol) of acetaldehyde ammonia trimer and 120 mL of anhydrous ethanol were placed in a 500 mL three-necked flask, the three-necked flask was placed in an ice water bath, the temperature of the ice water bath was controlled at 0°C, and uniform stirring was performed for 20 min to obtain a first solution.

[0100] (2) 51.3 g (0.465 mol) of vinyl sulfonyl fluoride (the structural formula is CH2=CH-SO2F) was introduced for reaction, the reaction time was 2.5 h, after the reaction was completed, the first intermediate was obtained by evaporation and rotary evaporation, ice water was added to the first intermediate for quenching reaction to obtain a second intermediate, the second intermediate was dissolved with dichloromethane, the organic phase was filtered, the organic phase was washed with 100 mL of 5 wt.% sodium chloride aqueous solution for 3 times, dried with 8 g of anhydrous magnesium sulfate, filtered, and concentrated to obtain a crude product. The crude product was cooled at -20°C for 2.8 h, filtered, and vacuum dried at 100°C for 24 h to obtain 59.8 g of compound four, and the yield of compound four was 84%.

[0101] 1H NMR (400 MHz, deuterated DMSO, ppm) of compound four: δ 1.14-1.18 (d, J = 3.2 Hz, 9H), 2.90-2.93 (t, J = 3.2 Hz, 6H), 3.48-3.51 (t, J = 3.6 Hz, 6H), 3.85-3.88 (dd, J = 5.6 Hz, 3H).

[0102] 13C{1H}NMR (100 MHz, deuterated DMSO, ppm) of compound four: δ 26.0, 40.9, 58.9, 58.9, 81.5.

[0103] The reaction equation for preparing compound four in this embodiment is as follows:

[0104]

[0105] Example 5

[0106] This embodiment is to prepare an alkali metal salt of a nitrogen-containing heterocyclic compound, and the preparation method comprises the following steps.

[0107] (1) 20 g (0.155 mol) of acetaldehyde ammonia trimer, 18.7 g (0.185 mol) of triethylamine and 120 mL of acetonitrile were charged into a 500 mL stainless steel autoclave, the jacket temperature of the reactor was set to 0°C, the cooling coil was passed through -10°C condensate water, and uniform stirring was carried out for 10 min to obtain a first solution.

[0108] (2) 15.8 g (0.155 mol) of sulfuryl fluoride gas was introduced for reaction, the reaction pressure was 0.5 MPa, the reaction time was 2.6 h, and after the reaction was completed, the intermediate was obtained by rotary evaporation and drying. The intermediate was dissolved with ethyl acetate, the organic phase was filtered, the organic phase was washed with 100 mL of 5 wt.% sodium chloride aqueous solution for 3 times, dried with 8 g of anhydrous magnesium sulfate, filtered, and concentrated to obtain a crude product. The crude product was cooled at -10°C for 3 h, filtered, and vacuum dried at 120°C for 12 h to obtain 30.1 g of the product.

[0109] (3) 20 g (0.095 mol) of the product and 100 mL of methanol were charged into a 500 mL three-necked flask to obtain a second solution. The three-necked flask was placed in a water bath, the temperature of the water bath was controlled at 50°C, uniform stirring was carried out for 25 min, 4.5 g (0.189 mol) of anhydrous lithium hydroxide was added in batches, the pH value was adjusted to 7.2, and the reaction was carried out for 2 h. After the reaction was completed, the product was concentrated, cooled at -10°C for 2 h, filtered, vacuum dried at 150°C for 24 h, and 18.0 g of compound five was obtained, and the yield of compound five was 85%.

[0110] 1H NMR (400MHz, deuterated DMSO, ppm) of compound five: δ 1.13-1.17 (d, J = 3.2 Hz, 9H), 3.85-3.88 (dd, J = 5.6 Hz, 3H).

[0111] 13C{1H} NMR (100MHz, deuterated DMSO, ppm) of compound five: δ 25.4, 35.0, 70.2, 82.7.

[0112] The reaction equation for preparing compound five in this example is as follows:

[0113]

[0114]

[0115] Second part: Application of nitrogen-containing heterocyclic compounds in batteries

[0116] 1.1 Preparation of non-aqueous electrolyte

[0117] In a glove box filled with nitrogen (O2<1 ppm, H2O <1 ppm), 86 g of mixed solvent obtained by mixing diethyl carbonate (DEC) and methyl ethyl carbonate (EMC) in a mass ratio of 1:1 was used as an organic solvent, and 1.5 g of each of the nitrogen-containing heterocyclic compounds prepared in Examples 1 to 6 was added to prepare a mixed solution. The mixed solution was sealed and frozen in a freezer (-4°C) for 2 h, and then taken out. In a glove box filled with nitrogen (O2<1 ppm, H2O <1 ppm), 12.5 g of lithium hexafluorophosphate (LiPF6) was slowly added to the mixed solution, and the mixture was uniformly mixed to prepare nonaqueous electrolytes 1 to 5.

[0118] In a glove box filled with nitrogen (O2<1 ppm, H2O <1 ppm), 87.5 g of mixed solvent obtained by mixing diethyl carbonate (DEC) and methyl ethyl carbonate (EMC) in a mass ratio of 1:1 was used as an organic solvent. The organic solvent was sealed and frozen in a freezer (-4°C) for 2 h, and then taken out. In a glove box filled with nitrogen (O2<1 ppm, H2O <1 ppm), 12.5 g of lithium hexafluorophosphate (LiPF6) was slowly added to the mixed solution, and the mixture was uniformly mixed to prepare nonaqueous electrolyte 6.

[0119] 1.2 Preparation of positive electrode sheet

[0120] Lithium iron phosphate, conductive agent Super P, binder PVDF, and carbon nanotube (CNT) were mixed in a mass ratio of 96.5:1.5:1:1 to prepare a lithium ion battery positive electrode slurry having a certain viscosity, which was coated on both sides of an aluminum foil, dried, and roll-pressed to obtain a positive electrode sheet, thereby preparing a lithium ion battery positive electrode sheet meeting the requirements.

[0121] 1.3 Preparation of negative electrode sheet

[0122] Artificial graphite, conductive agent Super P, thickening agent CMC, and binder SBR (styrene-butadiene rubber emulsion) were mixed in a mass ratio of 95:1.5:1.0:2.5 to prepare a slurry, which was uniformly mixed and coated on both sides of a copper foil, dried, and roll-pressed to obtain a negative electrode sheet, thereby preparing a lithium ion battery negative electrode sheet meeting the requirements.

[0123] 1.4 Preparation of lithium ion battery

[0124] The positive electrode sheet, the negative electrode sheet and the separator prepared by the above process were subjected to a lamination process to form a lithium ion battery with a thickness of 4.7 mm, a width of 55 mm, a length of 60 mm and a total capacity of 2 Ah, vacuum baked at 75°C for 10 h, and injected with non-aqueous electrolyte 1-6, respectively. After standing for 24 h, the battery was charged at a constant current of 0.1 C (200 mA) to 3.65 V, and then charged at a constant voltage of 3.65 V until the current decreased to 0.05 C (100 mA); then discharged at 0.2 C (400 mA) to 2.5 V, and the charging and discharging was repeated twice, and finally the battery was charged at 0.1 C (200 mA) to 3.65 V, to complete the lithium ion batteries 1-6.

[0125] The lithium ion batteries 1-6 were subjected to performance tests, and the test results are shown in Table 1, and the test conditions are as follows.

[0126] (1) High rate performance test

[0127] At room temperature (25°C), the lithium ion battery was subjected to one-time 3.0C / 3.0C charging and discharging (the battery discharge capacity was recorded as C0), and the upper limit voltage was 4.2 V; then 3.0C / 3.0C charging and discharging was performed for 500 cycles, and the capacity retention rate was calculated.

[0128] Capacity retention rate = (battery capacity after 500 cycles C1 / battery initial capacity C0) * 100%

[0129] (2) High temperature storage performance test

[0130] At room temperature (25°C), the lithium ion battery was subjected to one-time 0.5C / 0.5C charging and discharging (the battery discharge capacity was recorded as C0), and the upper limit voltage was 4.2 V, then the battery was charged to 4.2 V under the condition of 0.5C constant current and constant voltage, and the thickness of the battery was measured (the thickness was recorded as D0). The battery was placed in a 60°C oven for 30 d, taken out and measured for thickness (the thickness was recorded as D1), and placed in a 25°C environment for 0.5C discharging (the discharge capacity was recorded as C1), and the capacity retention rate and thickness expansion rate were calculated.

[0131] Capacity retention rate = (C1 / C0) * 100%

[0132] Thickness expansion rate = (D1-D0 / D0) * 100%

[0133] (3) High temperature cycle performance test

[0134] The lithium ion battery was charged and discharged at 1.0C / 1.0C (the battery discharge capacity was CO) at an upper voltage of 4.2V under high temperature (45℃) for one time, and then charged and discharged at 1.0C / 1.0C for 400 times (the battery discharge capacity was C1) under normal temperature, and the capacity retention rate was calculated.

[0135] Capacity retention rate = (C1 / C0)*100%

[0136] Table 1: Electrochemical performance test results of each example

[0137]

[0138] From the results in Table 1, it can be seen that the rate, high temperature storage and high temperature cycle performance of lithium ion batteries 1-5# are better than that of lithium ion battery 6#, which is because the nitrogen-containing heterocyclic compound is used as an additive in lithium ion batteries 1-5#. The nitrogen-containing heterocyclic compound can efficiently complex metal ions to avoid the dissolution of metal ions in the positive electrode of the battery. In addition, the active hydrogen protons are partially or completely replaced by sulfonyl fluoride or alkyl sulfonyl fluoride functional groups. The sulfonyl fluoride group can improve the ion conductivity and thermal stability of the nitrogen-containing heterocyclic compound, so the rate performance and high temperature performance of the battery are better.

[0139] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and are not intended to limit the scope of protection of the present application. Although the present application has been described in detail with reference to the preferred embodiments, it is not limited to the examples listed in the embodiments. Those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the essence and scope of the present application.

Claims

1. A nitrogen-containing heterocyclic compound, characterized by, Formula I wherein R1 is SO2F or CH2-(CH2) n -SO2F, R2 and R3 are each independently M, SO2F or CH2-(CH2) n -SO2F, n is an integer from 1 to 10, and M is hydrogen or an alkali metal, Formula I.

2. The nitrogen-containing heterocyclic compound according to claim 1, wherein n is an integer from 1 to 2, and M is hydrogen or lithium.

3. The nitrogenous heterocyclic compound according to claim 1, wherein at least one of Compound One to Compound Five, Compound One Compound Two Compound Three Compound Four Compound Five.

4. The process for producing a nitrogen-containing heterocyclic compound according to any one of claims 1 to 3, characterized by, comprising the steps of: (1) mixing acetaldehyde ammonia trimer and a first medium to form a first solution, the first medium being a first solvent or a combination of a first solvent and an organic base; (2) adding sulfuryl fluoride or alkenylsulfonyl fluoride to the first solution to react to obtain a product, purifying the product, and the alkenylsulfonyl fluoride has a structural formula of CH2=CH-(CH2) n-1 -SO2F, and n is an integer from 1 to 10.

5. The method for producing a nitrogen-containing heterocyclic compound according to Claim 4, wherein the first solvent comprising at least one of an alcohol solvent, a nitrile solvent, a halogenated hydrocarbon solvent, an ether solvent, an ester solvent and a ketone solvent, and the organic base comprising at least one of triethylamine, pyridine, 1,8-diazabicycloundec-7-ene and tetramethylpropylenediamine.

6. The method for producing a nitrogen-containing heterocyclic compound according to Claim 4, wherein the purification treatment comprising any one of Mode ① to Mode ③, Mode ①: pre-treatment after rough treatment, the pre-treatment comprising cooling crystallization or chromatographic column separation; Mode ②: after evaporation and rotary drying, using a second solvent for dissolution, and then taking the organic phase for washing, dehydration, filtration and concentration; Mode ③: after evaporation and rotary drying, quenching reaction, using a second solvent for dissolution, and then taking the organic phase for washing, dehydration, filtration and concentration.

7. The method for producing a nitrogen-containing heterocyclic compound according to Claim 4, wherein the molar ratio of the acetaldehyde ammonia trimer to the sulfonyl fluoride is 1:1.0-3.2 or the molar ratio of the acetaldehyde ammonia trimer to the alkenyl sulfonyl fluoride is 1:1.0-3.2, the certain temperature is -20-40℃ and the incubation time is 2-3h.

8. The method for producing an alkali metal salt of a nitrogen-containing heterocyclic compound according to any one of claims 1 to 3, characterized by, comprising the steps of: (1) mixing acetaldehyde ammonia trimer and a first medium to form a first solution, the first medium being a first solvent or a combination of a first solvent and an organic base; (ii) adding sulfuryl fluoride or alkenylsulfonyl fluoride, CH2=CH-(CH2) n-1 SO2F, n is an integer from 1 to 10, and the molar ratio of said acetaldehyde ammonia trimer to said sulfuryl fluoride is 1 : 2.0 to 2.2, or the molar ratio of said acetaldehyde ammonia trimer to said alkenylsulfonyl fluoride is 1 : 2.0 to 2.2, (3) mixing the first product with a third solvent to form a second solution, adding an alkali metal compound to the second solution and adjusting the pH value for reaction, and purifying the reactant.

9. Use of the nitrogen-containing heterocyclic compound according to any one of claims 1-3 as an electrolyte additive.

Images