Di(5-mononitroisosorbide) sulfate compound, preparation method thereof, and electrolyte

Abstract

The present invention provides a di(5-mononitroisosorbide) sulfate compound, a preparation method thereof, and an electrolyte. The structural formula of the di(5-mononitroisosorbide) sulfate compound of the present invention is shown in Formula I. The preparation method of the di(5-mononitroisosorbide) sulfate compound comprises the steps of: subjecting 5-mononitroisosorbide and thionyl chloride to an electrophilic addition reaction in the presence of a first solvent and an acid-binding agent to obtain an intermediate; adding an oxidizing agent to oxidize the intermediate in the presence of a second solvent to obtain a product; and purifying and drying the product. The di(5-mononitroisosorbide) sulfate compound has a mononitroisosorbide structure and a sulfonate structure, can form a good protective film at the interface of the positive and negative electrode materials, and has a low internal resistance, which can improve the battery's service life and cycle performance. Therefore, it is an excellent lithium-ion battery electrolyte additive that can expand the application field of 5-mononitroisosorbide derivatives. Formula I.

Description

Technical Field

[0001] The present invention relates to the technical field of material synthesis, in particular to a compound used in a battery, and more particularly to a di(5-mononitroisosorbide) sulfate compound, a preparation method thereof, and an electrolyte. Background Art

[0002] The electrolyte is the lifeblood of lithium-ion batteries, transporting lithium ions between the positive and negative electrode materials and the separator. Furthermore, the electrolyte plays a crucial role in the formation and impedance of the SEI and CEI at the interfaces of the positive and negative electrode materials. With the rapid development of pure electric and hybrid vehicles, demands for lithium-ion batteries' energy density, long cycle life, rate capability, and safety are continuously increasing. Lithium-ion battery cathode materials have shifted from lithium iron phosphate and lithium manganese oxide systems to ternary materials. In traditional electrolyte systems, ternary materials undergo significant interfacial catalytic reactions under high voltage and high temperature conditions, leading to electrolyte decomposition and gassing, which can compromise battery life and safety. Currently, the industry is looking to incorporate additives into the electrolyte that can form a film at the interface of the ternary cathode material to effectively protect the positive electrode, increase the electrolyte's voltage window, and enhance the battery's cycle life.

[0003] 5-Mononitroisosorbide derivatives refer to a series of compounds derived from the 5-nitroisosorbide group. Currently, 5-mononitroisosorbide derivatives are widely used clinically to treat cardiovascular diseases, primarily as nitric oxide donors. As nitric oxide donors, 5-mononitroisosorbide derivatives can rapidly release high concentrations of nitric oxide under physiological conditions, exerting its physiological effects.

[0004] Therefore, the current class of substances is targeted and not applicable to other technical fields. In order to expand the application areas of 5-mononitroisosorbide derivatives, the derivative groups of 5-mononitroisosorbide derivatives can be improved to find more 5-mononitroisosorbide derivatives that can be applied to other technical fields (such as lithium-ion batteries) to improve the service life and cycle performance of lithium-ion batteries. Summary of the Invention

[0005] Based on the above problems, the purpose of the present invention is to provide a di(5-mononitroisosorbide) sulfate compound, a preparation method thereof, and an electrolyte. The di(5-mononitroisosorbide) sulfate compound can be used in lithium-ion batteries to form a good protective film at the interface of positive and negative electrode materials, thereby improving the battery's service life and cycle performance.

[0006] To achieve the above objectives, the first aspect of the present invention provides a di(5-mononitroisosorbide) sulfate compound, the structural formula of which is shown in Formula I.

[0007]

[0008] Formula I

[0009] The bis(5-mononitroisosorbide) sulfate compound of the present invention is a compound represented by Formula I, which has a mononitroisosorbide structure and a sulfonate structure. It can form a good protective film at the interface of positive and negative electrode materials, which helps to improve the service life and cycle performance of the battery. Therefore, it is an excellent lithium-ion battery electrolyte additive and can expand the application field of 5-mononitroisosorbide derivatives.

[0010] The second aspect of the present invention provides a method for preparing a di(5-mononitroisosorbide) sulfate compound, comprising the steps of:

[0011] (1) In the presence of a first solvent and an acid-binding agent, 5-mononitroisosorbide and thionyl chloride undergo an electrophilic addition reaction to obtain an intermediate;

[0012] (2) adding an oxidant in a second solvent to carry out an oxidation reaction on the intermediate to obtain a product;

[0013] (3) Purifying and drying the product.

[0014] The preparation method of the present invention is simple. It involves an electrophilic addition reaction between 5-mononitroisosorbide and thionyl chloride catalyzed by an acid-binding agent, followed by an oxidation reaction. The resulting di(5-mononitroisosorbide) sulfate compound can improve the battery's service life and cycle performance.

[0015] As a technical solution of the present invention, the first solvent includes at least one of dichloromethane, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, 1,4-dioxane, toluene, acetonitrile, ether, tetrahydrofuran, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate and propylene carbonate.

[0016] As a technical solution of the present invention, the acid binding agent includes at least one of triethylamine, pyridine and 1,8-diazabicyclo[5.4.0]undec-7-ene.

[0017] As a technical solution of the present invention, the molar ratio of the thionyl chloride to the 5-mononitroisosorbide is 1:2-4, and the molar ratio of the acid binding agent to the 5-mononitroisosorbide is 1-4:1.

[0018] As a technical solution of the present invention, the second solvent includes at least one of dichloromethane, chloroform, carbon tetrachloride, benzene, cyclohexane and 1,4-dioxane.

[0019] As a technical solution of the present invention, the oxidant includes at least one of hydrogen peroxide, sodium hypochlorite, sodium periodate, iodobenzene acetate, m-chloroperbenzoic acid, potassium permanganate and oxygen.

[0020] As a technical solution of the present invention, the molar ratio of the oxidant to the intermediate is 1-4:1.

[0021] As a technical solution of the present invention, the reaction temperature of the electrophilic addition reaction is -20~40°C, the reaction time of the electrophilic addition reaction is 0.5~4.0h, the reaction temperature of the oxidation reaction is 0~40°C, and the reaction time of the oxidation reaction is 3~10h.

[0022] As a technical solution of the present invention, the purification method is washing, filtration or recrystallization.

[0023] A third aspect of the present invention provides use of a di(5-mononitroisosorbide) sulfate compound in a battery.

[0024] The fourth aspect of the present invention provides an electrolyte solution comprising a non-aqueous organic solvent, an electrolyte salt and an additive.

[0025] The additive includes the aforementioned di(5-mononitroisosorbide) sulfate compound, and the di(5-mononitroisosorbide) sulfate compound accounts for 0.1-5.0% of the mass of the electrolyte. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the hydrogen spectrum of the di(5-mononitroisosorbide) sulfite compound of Example 1.

[0027] Figure 2 This is the hydrogen spectrum of the di(5-mononitroisosorbide) sulfate compound of Example 1.

[0028] Figure 3 This is the carbon spectrum of the di(5-mononitroisosorbide) sulfate compound of Example 1. DETAILED DESCRIPTION

[0029] The bis(5-mononitroisosorbide) sulfate compound of the present invention can be used in material synthesis, pharmaceutical intermediates, and batteries. In particular, the bis(5-mononitroisosorbide) sulfate compound is used in lithium-ion batteries. As an electrolyte additive, the bis(5-mononitroisosorbide) sulfate compound can improve the electrochemical performance of lithium-ion batteries, including low-temperature performance and rate capability.

[0030] Lithium-ion batteries include positive electrode active materials, negative electrode active materials, and electrolytes. The positive electrode active materials may be layered transition metal lithium oxides or olivine-type lithium compounds. Layered transition metal lithium oxides may be, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (chemical formula LiNi x Co y Mn (1-x-y) M z O2, where 0.6 ≤ x < 0.9, x + y < 1, 0 ≤ z < 0.08, and M is at least one of Al, Mg, Zr, and Ti), and coatings and dopants of the above materials. They are particularly suitable for lithium nickel cobalt manganese oxide ternary materials. These positive electrode active materials can be used alone or in combination of two or more.

[0031] The negative electrode active material includes at least one of a carbon-based material, a silicon-based material, and a tin-based material. The carbon-based material may 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 may be, but is not limited to, at least one of simple silicon, a silicon-oxygen composite material, a silicon-carbon composite material, and a silicon alloy material. The tin-based material may include simple tin, a tin-carbon composite material, a tin-oxygen composite material, or a tin alloy compound.

[0032] The electrolyte solution includes an electrolyte salt, a non-aqueous organic solvent, and additives.

[0033] The electrolyte salt may be, but is not limited to, at least one of lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), lithium bis(fluorosulfonyl imide) (LiFSI), lithium bis(trifluoromethylsulfonyl imide) (LiTFSI), lithium methanesulfonate (LiCH3SO3), lithium trifluoromethylsulfonate (LiCF3SO3), lithium bis(oxalatoborate) (C4BLiO8), lithium difluorooxalatoborate (C2BF2LiO4), lithium difluorophosphate (LiPO2F2), and lithium difluorobis(oxalatophosphate) (LiDFBP). The non-aqueous organic solvent is selected from carbonates and / or carboxylates. Further, the non-aqueous organic solvent is selected from at least one of ethylene 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.

[0034] The additive is a di(5-mononitroisosorbide) sulfate compound. Further, the additive is a compound represented by Formula I.

[0035]

[0036] Formula I

[0037] The di(5-mononitroisosorbide) sulfate compound accounts for 0.1-5.0% of the mass of the electrolyte. As an example, the proportion of the di(5-mononitroisosorbide) sulfate compound can be, but is not limited to, 0.1%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, and 5.0%.

[0038] The preparation method of di(5-mononitroisosorbide) sulfate compound comprises the steps of:

[0039] (1) In the presence of a first solvent and an acid-binding agent, 5-mononitroisosorbide and thionyl chloride undergo an electrophilic addition reaction to obtain an intermediate;

[0040] (2) adding an oxidant in a second solvent to oxidize the intermediate to obtain a product;

[0041] (3) Purify and dry the product.

[0042] The reaction process of di(5-mononitroisosorbide) sulfate compound is shown below.

[0043]

[0044] intermediates

[0045]

[0046] Wherein, in step (1), the first solvent includes at least one of dichloromethane, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, 1,4-dioxane, toluene, acetonitrile, ether, tetrahydrofuran, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate and propylene carbonate, preferably dichloromethane. The content of the first solvent can be regulated according to actual conditions, and it needs to meet the reaction conditions required for the dissolution of the reactants and the electrophilic addition reaction. The acid binding agent includes at least one of triethylamine, pyridine and 1,8-diazabicyclo[5.4.0]undec-7-ene, preferably triethylamine or pyridine. The reaction temperature of the electrophilic addition reaction is -20~40℃, preferably -10~25℃, and as an example, it can be but not limited to -20℃, -15℃, -10℃, -5℃, 0℃, 5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, 40℃. The reaction time of the electrophilic addition reaction is 0.5 to 4.0 hours, preferably 2.0 to 4.0 hours, and as an example, it can be, but is not limited to, 0.5 hours, 1.0 hours, 1.5 hours, 2.0 hours, 2.5 hours, 3.0 hours, 3.5 hours, or 4.0 hours. The molar ratio of thionyl chloride to 5-mononitroisosorbide is 1:2 to 4. As an example, the molar ratio can be, but is not limited to, 1:2, 1:3, or 1:4. Preferably, the molar ratio of thionyl chloride to 5-mononitroisosorbide is 1:2. The molar ratio of the acid binding agent to 5-mononitroisosorbide is 1 to 4:1. As an example, it can be, but is not limited to, 1:1, 2:1, 3:1, or 4:1. Preferably, the molar ratio of the acid binding agent to 5-mononitroisosorbide is 2:1.

[0047] The second solvent includes at least one of dichloromethane, chloroform, carbon tetrachloride, benzene, cyclohexane, and 1,4-dioxane, preferably dichloromethane. The content of the second solvent can be adjusted based on actual conditions, and should meet the reaction conditions required for the dissolution of the reactants and the oxidation reaction. The oxidant includes at least one of hydrogen peroxide, sodium hypochlorite, sodium periodate, iodobenzene acetate, meta-chloroperbenzoic acid, potassium permanganate, and oxygen, preferably meta-chloroperbenzoic acid. The molar ratio of the oxidant to the intermediate is 1 to 4:1. By way of example, the molar ratio may be, but is not limited to, 1:1, 2:1, 3:1, or 4:1. The reaction temperature of the oxidation reaction is 0 to 40°C, preferably 10 to 30°C. By way of example, the reaction temperature may 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. The reaction time of the oxidation reaction is 3 to 10 hours, preferably 3 to 6 hours. As an example, it can be, but is not limited to, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, and 10 hours.

[0048] In step (3), after the oxidation reaction is completed, the product is quenched and purified by extraction, concentration, washing, filtration or recrystallization. Washing can be performed with aqueous hydrochloric acid, saturated saline or water and repeated washing. Filtration can be performed by centrifugal stratification, vacuum filtration or ordinary filtration. Recrystallization can be performed with a mixed solvent of ethanol / water, and drying can be performed with anhydrous sodium sulfate.

[0049] In order to better illustrate the purpose, technical solutions and beneficial effects of the present invention, the present invention will be further described below in conjunction with specific embodiments. It should be noted that the following implementation method is a further explanation of the present invention and should not be used as a limitation of the present invention.

[0050] Part I: Preparation of di(5-mononitroisosorbide) sulfate compounds

[0051] Example 1

[0052] This embodiment is to prepare di(5-mononitroisosorbide) sulfate compound, and its preparation method includes the following steps.

[0053] (1) Add 200 ml of dichloromethane, 20 g of 5-mononitroisosorbide, and 10.6 g of triethylamine to a 500 ml three-necked flask, stir for 30 min, cool to 0-5 °C, and slowly add a dichloromethane solution containing 6.2 g of thionyl chloride. After the addition is complete, remove the ice bath and react at room temperature for 3 h. After the reaction is complete, filter and remove triethylamine hydrochloride. Pour the reaction solution into ice water, let it stand and separate. Wash the organic phase with saturated salt water and water in turn, combine the organic phases, and then dry with anhydrous sodium sulfate to remove dichloromethane to obtain the intermediate, 21.5 g of white solid. The structure of the obtained white solid was confirmed, and the results are shown in the attached figure. Figure 1 As shown, the hydrogen spectrum ( 1 H NMR, 400 MHz, DMSO- d 6) The structure was consistent with the target, indicating that di(5-mononitroisosorbide) sulfite compound was synthesized.

[0054] (2) Add 200 ml of dichloromethane and 21.5 g of the intermediate to a 500 ml three-necked flask, stir until dissolved, cool to 0-5 °C, and slowly add a dichloromethane solution containing 10.39 g of chloroperbenzoic acid. After the addition is complete, remove the ice bath and react at room temperature for 5 h.

[0055] (3) Add 10 wt.% sodium thiosulfate solution to quench the mixture, wash twice with saturated sodium bicarbonate solution and saturated brine, collect the organic layer and dry it with anhydrous sodium sulfate, concentrate it to obtain a white solid crude product, and recrystallize it with 100 ml of anhydrous ethanol to obtain 18.7 g of di(5-mononitroisosorbide) sulfate, with a yield of 83.9%. The structure of the obtained white solid was confirmed, and the results are shown in the attached figure. Figures 2 and 3 As shown, the hydrogen spectrum ( 1 H NMR, 400 MHz, DMSO- d 6) Carbon spectrum ( 13 C NMR, 400 MHz, DMSO- d 6) The result is consistent with the target structure, indicating that the di(5-mononitroisosorbide) sulfate compound with the structural formula shown in Formula I has been synthesized.

[0056] Example 2

[0057] This embodiment is to prepare di(5-mononitroisosorbide) sulfate compound, and its preparation method includes the following steps.

[0058] (1) In a 500ml three-necked flask, add 300ml of N,N-dimethylacetamide, 30g of 5-mononitroisosorbide, and 11.8g of pyridine, stir for 45min, cool to 0~5℃, slowly add N,N-dimethylacetamide solution containing 5.8g of thionyl chloride, remove the ice bath after the addition is complete, react at room temperature for 4h, filter to remove pyridine hydrochloride after the reaction is complete, pour the reaction solution into ice water, let it stand and separate, wash the organic phase with saturated brine and water in turn, combine the organic phases, and then dry with anhydrous sodium sulfate to remove N,N-dimethylacetamide to obtain the intermediate, 26.7g of white solid.

[0059] (2) Add 400 ml of dichloromethane and 26.1 g of the intermediate to a 500 ml three-necked flask, stir until dissolved, cool to 0-5 °C, and slowly add a dichloromethane solution containing 20.1 g of iodobenzene acetate. After the addition is complete, remove the ice bath and react at room temperature for 6 h.

[0060] (3) The mixture was quenched by adding 13 wt.% sodium thiosulfate solution, washed twice with saturated sodium bicarbonate solution and saturated brine, the organic layer was collected and dried over anhydrous sodium sulfate, and concentrated to obtain a white solid crude product, which was recrystallized from 100 ml of anhydrous ethanol to obtain 23.1 g of di(5-mononitroisosorbide) sulfate, with a yield of 85.3%.

[0061] Part II: Application of di(5-mononitroisosorbide) sulfate compounds in batteries

[0062] 1.1 Preparation of non-aqueous electrolyte:

[0063] In a nitrogen-filled glove box (O<1 ppm, H<1 ppm), 86 g of a mixed solvent was prepared by mixing diethyl carbonate (DEC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC) in a mass ratio of 3:1:2. 0.5 g of each of the di(5-mononitroisosorbide) sulfate compounds prepared in Examples 1 and 2 was added to form a mixed solution. The mixed solution was sealed, packaged, and placed in a quick freezer (-4°C) for 2 hours. After removal, 13 g of lithium hexafluorophosphate (LiPF) was slowly added to the mixed solution in a nitrogen-filled glove box (O<1 ppm, H<1 ppm). After mixing, non-aqueous electrolyte solutions 1 and 2 were prepared.

[0064] In a nitrogen-filled glove box (O2 <1ppm, H2O <1ppm), diethyl carbonate (DEC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC) were mixed in a mass ratio of 3:1:2 to obtain 87g of a mixed solvent as an organic solvent. The organic solvent was sealed and packaged and placed in a quick freezer (-4°C) for 2 hours before being taken out. In a nitrogen-filled glove box (O2 <1ppm, H2O <1ppm), 13g of lithium hexafluorophosphate (LiPF6) was slowly added to the mixed solution and mixed thoroughly to prepare non-aqueous electrolyte solution 3#.

[0065] 1.2 Preparation of positive electrode sheet:

[0066] The ternary material LiNi 0.5 Co 0.2 Mn 0.3 Zr 0.03 O2, conductive agent SuperP, adhesive PVDF and carbon nanotubes (CNT) are evenly mixed in a mass ratio of 96.5:1.5:1:1 to form a lithium-ion battery positive electrode slurry with a certain viscosity. After coating it on both sides of aluminum foil, it is dried and rolled to obtain a positive electrode sheet, making a lithium-ion battery positive electrode sheet that meets the requirements.

[0067] 1.3 Preparation of negative electrode sheet:

[0068] Artificial graphite is mixed with a conductive agent SuperP, a thickener CMC, and an adhesive SBR (styrene-butadiene rubber latex) in a mass ratio of 95:1.5:1.0:2.5 to prepare a slurry, which is then evenly mixed. The mixed slurry is then coated on both sides of a copper foil, and then dried and rolled to obtain a negative electrode sheet, thereby making a lithium-ion battery negative electrode sheet that meets the requirements.

[0069] 1.4 Preparation of lithium-ion batteries:

[0070] The positive electrode sheet, negative electrode sheet, and separator prepared according to the above process were laminated to form lithium-ion batteries with a thickness of 4.7mm, a width of 55mm, a length of 60mm, and a total capacity of 2Ah. They were vacuum-baked at 75°C for 10 hours and then injected with non-aqueous electrolyte 1#, non-aqueous electrolyte 2#, and non-aqueous electrolyte 3#, respectively. After standing for 24 hours, they were charged to 3.65V at a constant current of 0.1C (200mA), then charged at a constant voltage of 3.65V until the current dropped to 0.05C (100mA). They were then discharged to 2.5V at 0.2C (400mA), repeated twice, and finally charged to 3.65V at 0.1C (200mA). This completed the production of button-type lithium-ion battery 1#, button-type lithium-ion battery 2#, and button-type lithium-ion battery 3#.

[0071] Performance testing was conducted on button-type lithium-ion battery #1, button-type lithium-ion battery #2, and button-type lithium-ion battery #3. The test results are shown in Table 1. The test conditions are as follows. At room temperature (25°C), the button-type batteries were charged and discharged once at a 3.0C / 3.0C rate (the battery discharge capacity is recorded as C0) with an upper voltage limit of 4.1V. The batteries were then charged and discharged at a 3.0C / 3.0C rate for 300 cycles, and the capacity retention was calculated.

[0072] Capacity retention rate = (battery capacity C1 after 300 cycles / battery initial capacity C0) * 100%

[0073] Table 1 Electrochemical performance test results

[0074]

[0075] From the results in Table 1, it can be seen that the cycle performance of button-type lithium-ion battery 1# and button-type lithium-ion battery 2# is better than that of button-type lithium-ion battery 3#. This is because button-type lithium-ion battery 1# and button-type lithium-ion battery 2# use di(5-mononitroisosorbide) sulfate as an additive. Di(5-mononitroisosorbide) sulfate has a mononitroisosorbide structure and a sulfonate structure, which can form a good protective film at the interface of the positive and negative electrode materials, thereby improving the cycle performance of the battery.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the scope of protection of the present invention. Although the present invention is described in detail with reference to the preferred embodiments, it is not limited to those listed in the embodiments. Those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A di(5-mononitroisosorbide) sulfate compound, characterized in that: The structural formula is shown in Formula I, Formula I.

2. The method for preparing a di(5-mononitroisosorbide) sulfate compound according to claim 1, wherein: Including steps: (1) In the presence of a first solvent and an acid-binding agent, 5-mononitroisosorbide and thionyl chloride undergo an electrophilic addition reaction to obtain an intermediate; (2) adding an oxidant in a second solvent to carry out an oxidation reaction on the intermediate to obtain a product; (3) Purifying and drying the product.

3. The method for preparing a di(5-mononitroisosorbide) sulfate compound according to claim 2, wherein: The first solvent includes at least one of dichloromethane, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, 1,4-dioxane, toluene, acetonitrile, diethyl ether, tetrahydrofuran, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate and propylene carbonate.

4. The method for preparing a di(5-mononitroisosorbide) sulfate compound according to claim 2, wherein: The acid binding agent includes at least one of triethylamine, pyridine and 1,8-diazabicyclo[5.4.0]undec-7-ene.

5. The method for preparing the di(5-mononitroisosorbide) sulfate compound according to claim 2, wherein: The molar ratio of the thionyl chloride to the 5-mononitroisosorbide is 1:2-4, and the molar ratio of the acid binding agent to the 5-mononitroisosorbide is 1-4:

1.

6. The method for preparing the di(5-mononitroisosorbide) sulfate compound according to claim 2, wherein: The second solvent includes at least one of dichloromethane, chloroform, carbon tetrachloride, benzene, cyclohexane and 1,4-dioxane.

7. The method for preparing bis(5-mononitroisosorbide) sulfate compound according to claim 2, characterized in that: The oxidant includes at least one of hydrogen peroxide, sodium hypochlorite, sodium periodate, iodobenzene acetate, m-chloroperbenzoic acid, potassium permanganate and oxygen.

8. The method for preparing a di(5-mononitroisosorbide) sulfate compound according to claim 2, wherein: The molar ratio of the oxidant to the intermediate is 1 to 4:

1.

9. The method for preparing a di(5-mononitroisosorbide) sulfate compound according to claim 2, wherein: The reaction temperature of the electrophilic addition reaction is -20-40° C., the reaction time of the electrophilic addition reaction is 0.5-4.0 h, the reaction temperature of the oxidation reaction is 0-40° C., and the reaction time of the oxidation reaction is 3-10 h.

10. An electrolyte solution comprising a non-aqueous organic solvent, an electrolyte salt and an additive, characterized in that: The additive includes the di(5-mononitroisosorbide) sulfate compound according to claim 1 or the di(5-mononitroisosorbide) sulfate compound prepared by the preparation method of the di(5-mononitroisosorbide) sulfate compound according to any one of claims 2 to 9, and the di(5-mononitroisosorbide) sulfate compound accounts for 0.1 to 5.0% by mass of the electrolyte.

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