Bis (5-mononitro isosorbide) sulfate compound, preparation method thereof and electrolyte

Abstract

The invention provides a sulfuric acid di (5-mononitro isosorbide) ester compound, a preparation method thereof and an electrolyte. The structural formula of the sulfuric acid di (5-mononitro isosorbide) ester compound is shown as a formula I in the specification. The preparation method of the sulfuric acid di (5-mononitro isosorbide) ester compound comprises the following steps: carrying out electrophilic addition reaction on 5-mononitro isosorbide and thionyl chloride in the presence of a first solvent and an acid-binding agent to obtain an intermediate; in a second solvent, adding an oxidizing agent to carry out oxidation reaction on the intermediate to obtain a product; and purifying and drying the product. The sulfuric acid di (5-mononitro isosorbide) ester compound has a mononitro isosorbide structure and a sulfonate structure, can form a good protective film on an interface of a positive electrode material and a negative electrode material, has relatively small internal resistance, and can improve the service life and the cycle performance of a battery, so that the sulfuric acid di (5-mononitro isosorbide) ester compound is an excellent lithium ion battery electrolyte additive; the application field of the 5-mononitro isosorbide derivative can be expanded. And the formula I of the # imgabs0 # is shown in the specification.

Description

Technical Field

[0001] The present invention relates to the technical field of material synthesis, and 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 blood of lithium-ion batteries. It plays a role in transferring lithium ions between the positive and negative electrode materials and the separator. In addition, the electrolyte also plays an important role in the formation of SEI and CEI at the interface of the positive and negative electrode materials and the impedance size. With the rapid development of pure electric vehicles and hybrid vehicles, people's requirements for the energy density, long cycle life, rate performance and safety performance of lithium-ion batteries are constantly increasing. The positive electrode material of lithium-ion batteries has shifted from lithium iron phosphate and lithium manganese oxide systems to ternary material systems. In traditional electrolyte systems, ternary materials will undergo obvious interfacial catalytic reactions under high voltage and high temperature conditions, resulting in the decomposition and gas production of the electrolyte. Whether the life and safety of the battery can be guaranteed. At present, the industry hopes to add some additives that can form a film at the interface of the ternary positive electrode material to the electrolyte to effectively protect the positive electrode, improve the pressure window of the electrolyte, and improve the cycle life of the battery.

[0003] 5-mononitroisosorbide derivatives refer to a series of compounds derived from the 5-nitroisosorbide group. At present, 5-mononitroisosorbide derivatives are mainly used as nitric oxide donors and have been widely used in the treatment of cardiovascular diseases in clinic. As nitric oxide donors, 5-mononitroisosorbide derivatives can quickly release high concentrations of nitric oxide under physiological conditions and exert the physiological effects of nitric oxide.

[0004] Therefore, the current substances are targeted and are not applicable to other technical fields. In order to expand the application field of 5-mononitroisosorbide derivatives, the derivative groups of 5-mononitroisosorbide derivatives can be improved to seek 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 and 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 service life and cycle performance of the battery.

[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 The di(5-mononitroisosorbide) sulfate compound of the present invention is a compound shown in Formula I, which has a mononitroisosorbide structure and a sulfonate structure, and can form a good protective film at the interface of the 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.

[0009] The second aspect of the present invention provides a method for preparing a di(5-mononitroisosorbide) sulfate compound, comprising the steps of: (1) in the presence of a first solvent and an acid-binding agent, subjecting 5-mononitroisosorbide and thionyl chloride to an electrophilic addition reaction to obtain an intermediate; (2) adding an oxidant in a second solvent to carry out an oxidation reaction of the intermediate to obtain a product; (3) Purifying and drying the product.

[0010] The preparation method of the present invention is simple, and the preparation method can be prepared by performing an electrophilic addition reaction of 5-mononitroisosorbide and thionyl chloride under the catalysis of an acid-binding agent, and then performing an oxidation reaction. The prepared di(5-mononitroisosorbide) sulfate ester compound can improve the service life and cycle performance of the battery.

[0011] 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. 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. 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.

[0012] 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. As a technical solution of the present invention, the oxidant includes at least one of hydrogen peroxide, sodium hypochlorite, sodium periodate, iodobenzene acetate, meta-chloroperbenzoic acid, potassium permanganate and oxygen.

[0013] As a technical solution of the present invention, the molar ratio of the oxidant to the intermediate is 1-4:1.

[0014] 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.

[0015] As a technical solution of the present invention, the purification method is washing, filtering or recrystallization.

[0016] The third aspect of the present invention provides the use of di(5-mononitroisosorbide) sulfate compound in a battery.

[0017] The fourth aspect of the present invention provides an electrolyte solution comprising a non-aqueous organic solvent, an electrolyte salt and an additive. 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 Figure 1 This is the hydrogen spectrum of the di(5-mononitroisosorbide) sulfite compound of Example 1.

[0018] Figure 2 This is the hydrogen spectrum of the di(5-mononitroisosorbide) sulfate compound of Example 1.

[0019] Figure 3 This is the carbon spectrum of the di(5-mononitroisosorbide) sulfate compound of Example 1. DETAILED DESCRIPTION

[0020] The di(5-mononitroisosorbide) sulfate compound of the present invention can be used in material synthesis, pharmaceutical intermediates, and batteries. In particular, the di(5-mononitroisosorbide) sulfate compound is used in lithium-ion batteries. The di(5-mononitroisosorbide) sulfate compound can be used as an electrolyte additive to improve the electrochemical properties of lithium-ion batteries, such as low temperature and rate.

[0021] 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. The layered transition metal lithium oxides may be, but are not limited to, lithium cobalt oxides (such as LiCoO2), lithium nickel oxides (such as LiNiO2), lithium manganese oxides (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, lithium nickel cobalt manganese oxides (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 coatings and dopants of the above materials. It is 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.

[0022] 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 may be, but is not limited to, at least one of artificial graphite, natural graphite, hard carbon, soft carbon, graphene and mesophase carbon microspheres. The silicon-based material may be, but is not limited to, at least one of a silicon element, a silicon-oxygen composite material, a silicon-carbon composite material and a silicon alloy material. The tin-based material may include a tin element, a tin-carbon composite material, a tin-oxygen composite material, and a tin alloy compound.

[0023] The electrolyte solution includes an electrolyte salt, a nonaqueous organic solvent, and additives.

[0024] 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(oxalate)borate (C4BLiO8), lithium difluorooxalate borate (C2BF2LiO4), lithium difluorophosphate (LiPO2F2) and lithium difluorobis(oxalate)phosphate (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.

[0025] The additive is a di(5-mononitroisosorbide) sulfate compound, and further, the additive is a compound shown in formula I.

[0026]

[0027] Formula I 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%.

[0028] The preparation method of di(5-mononitroisosorbide) sulfate compound comprises the steps of: (1) in the presence of a first solvent and an acid-binding agent, subjecting 5-mononitroisosorbide and thionyl chloride to an electrophilic addition reaction to obtain an intermediate; (2) adding an oxidant in a second solvent to carry out an oxidation reaction of the intermediate to obtain a product; (3) Purify and dry the product.

[0029] The reaction process of di(5-mononitroisosorbide) sulfate compound is shown below.

[0030]

[0031] Intermediates

[0032] 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°C, preferably -10~25°C, as an example, it can be but 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, 40°C. The reaction time of the electrophilic addition reaction is 0.5 to 4.0 hours, preferably 2.0 to 4.0 hours, as an example, it can be but not limited to 0.5 hours, 1.0 hours, 1.5 hours, 2.0 hours, 2.5 hours, 3.0 hours, 3.5 hours, 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 not limited to 1:2, 1:3, 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 not limited to 1:1, 2:1, 3:1, 4:1, preferably, the molar ratio of the acid binding agent to 5-mononitroisosorbide is 2:1.

[0033] 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 regulated according to actual conditions, and it needs to 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. As an example, the molar ratio can be but not limited to 1:1, 2:1, 3:1, 4:1. The reaction temperature of the oxidation reaction is 0 to 40°C, preferably 10 to 30°C, as an example, it can be but not limited to 0°C, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 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 not limited to 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, and 10 hours.

[0034] In step (3), the oxidation reaction is quenched after completion, and the purification method is extraction, concentration, washing, filtration or recrystallization. Among them, washing can be carried out by aqueous hydrochloric acid solution, saturated saline or water and multiple washings. Filtration can be carried out by centrifugal stratification, vacuum filtration or ordinary filtration. Recrystallization can be carried out by a mixed solvent of ethanol / water, and drying can be carried out by anhydrous sodium sulfate.

[0035] In order to better illustrate the purpose, technical scheme 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.

[0036] Part I: Preparation of di(5-mononitroisosorbide) sulfate compounds Example 1 This embodiment is to prepare di(5-mononitroisosorbide) sulfate compound, and its preparation method includes the following steps.

[0037] (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, slowly add a dichloromethane solution containing 6.2 g of thionyl chloride, remove the ice bath after the addition is complete, react at room temperature for 3 h, filter to remove triethylamine hydrochloride after the reaction is complete, pour the reaction solution into ice water, let 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 dichloromethane to obtain an intermediate, 21.5 g of a 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.

[0038] (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.

[0039] (3) 10 wt.% sodium thiosulfate solution was added to quench the mixture, and the mixture was washed twice with saturated sodium bicarbonate solution and saturated brine in sequence. The organic layer was collected and dried over anhydrous sodium sulfate, and concentrated to obtain a crude white solid product, which was recrystallized from 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. Figure 2~3 As shown, the hydrogen spectrum ( 1 H NMR, 400 MHz, DMSO- d 6) Carbon spectrum ( 13 C NMR, 400 MHz, DMSO- d 6) 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.

[0040] Example 2 This embodiment is to prepare di(5-mononitroisosorbide) sulfate compound, and its preparation method includes the following steps.

[0041] (1) In a 500 ml three-necked flask, add 300 ml of N,N-dimethylacetamide, 30 g of 5-mononitroisosorbide, and 11.8 g of pyridine. Stir for 45 min, cool to 0-5 °C, slowly add N,N-dimethylacetamide solution containing 5.8 g of thionyl chloride, remove the ice bath after the addition is complete, react at room temperature for 4 h, filter to remove pyridine hydrochloride after the reaction is complete, pour the reaction solution into ice water, let stand to separate, wash the organic phase with saturated brine and water in turn, combine the organic phases, and then dry over anhydrous sodium sulfate to remove N,N-dimethylacetamide to obtain the intermediate, obtaining 26.7 g of white solid.

[0042] (2) In a 500 ml three-necked flask, add 400 ml of dichloromethane and 26.1 g of the intermediate, stir until dissolved, cool to 0-5 °C, slowly add a dichloromethane solution containing 20.1 g of iodobenzene acetate, remove the ice bath after the addition is complete, and react at room temperature for 6 h.

[0043] (3) The mixture was quenched by adding 13 wt.% sodium thiosulfate solution, washed twice with saturated sodium bicarbonate solution and saturated brine in sequence, 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%.

[0044] Part II: Application of di(5-mononitroisosorbide) sulfate compounds in batteries 1.1 Preparation of non-aqueous electrolyte: In a glove box filled with nitrogen (O2 <1ppm, H2O <1ppm), 86g of the mixed solvent obtained by mixing diethyl carbonate (DEC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC) in a mass ratio of 3:1:2 was used as an organic solvent, and 0.5g of the di(5-mononitroisosorbide) sulfate compound prepared in Example 1 and Example 2 was added to obtain a mixed solution. The mixed solution was sealed and packaged and placed in a quick freezer (-4°C) for 2h and then taken out. In a glove box filled with nitrogen (O2 <1ppm, H2O <1ppm), 13g of lithium hexafluorophosphate (LiPF6) was slowly added to the mixed solution, and non-aqueous electrolyte 1# and non-aqueous electrolyte 2# were prepared after mixing.

[0045] In a glove box filled with nitrogen (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 2h before being taken out. In a glove box filled with nitrogen (O2 <1ppm, H2O <1ppm), 13g of lithium hexafluorophosphate (LiPF6) was slowly added to the mixed solution, and non-aqueous electrolyte 3# was prepared after mixing evenly.

[0046] 1.2 Preparation of positive electrode: 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, which is then coated on both sides of an aluminum foil and dried and rolled to obtain a positive electrode sheet, thereby making a lithium-ion battery positive electrode sheet that meets the requirements.

[0047] 1.3 Preparation of negative electrode sheet: Artificial graphite is mixed with conductive agent SuperP, thickener CMC and adhesive SBR (styrene-butadiene rubber latex) in a mass ratio of 95:1.5:1.0:2.5 to make a slurry, which is evenly mixed. The mixed slurry is applied on both sides of the 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.

[0048] 1.4 Preparation of lithium-ion batteries: The positive electrode sheet, negative electrode sheet and diaphragm prepared according to the above process were laminated to form a lithium-ion battery 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 10h and injected with non-aqueous electrolyte 1#, non-aqueous electrolyte 2# and non-aqueous electrolyte 3# respectively. After standing for 24h, they were charged to 3.65V with a constant current of 0.1C (200mA), and then charged with a constant voltage of 3.65V until the current dropped to 0.05C (100mA); then discharged to 2.5V with 0.2C (400mA), repeated twice, and finally charged to 3.65V with 0.1C (200mA), completing the production of button-type lithium-ion battery 1#, button-type lithium-ion battery 2# and button-type lithium-ion battery 3#.

[0049] The button type lithium ion battery 1#, button type lithium ion battery 2#, and button type lithium ion battery 3# were subjected to performance tests. The test results are shown in Table 1. The test conditions are as follows. At room temperature (25°C), the button type battery was charged and discharged at 3.0C / 3.0C (the battery discharge capacity was recorded as C0), the upper limit voltage was 4.1V, and then charged and discharged at 3.0C / 3.0C for 300 weeks, and the capacity retention rate was calculated.

[0050] Capacity retention rate = (battery capacity C1 after 300 cycles / battery initial capacity C0) * 100% Table 1 Electrochemical performance test results

[0051] 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 compound as an additive, which has a mononitroisosorbide structure and a sulfonate structure, and can form a good protective film at the interface of the positive and negative electrode materials, thereby improving the cycle performance of the battery.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution 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 solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution 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 di(5-mononitroisosorbide) sulfate compound according to claim 1, characterized in that: Includes steps: (1) in the presence of a first solvent and an acid-binding agent, subjecting 5-mononitroisosorbide and thionyl chloride to an electrophilic addition reaction to obtain an intermediate; (2) adding an oxidant in a second solvent to carry out an oxidation reaction of the intermediate to obtain a product; (3) Purifying and drying the product.

3. The method for preparing the di(5-mononitroisosorbide) sulfate compound according to claim 2, characterized in that: 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.

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

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

1.

9. The method for preparing di(5-mononitroisosorbide) sulfate compound according to claim 1, characterized in that: 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.

10. An electrolyte solution comprising a non-aqueous organic solvent, an electrolyte salt and an additive, characterized in that: The additive comprises 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% of the mass of the electrolyte.

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