Preparation method of methylene methyldisulfonate, electrolyte, battery, battery pack and electric equipment

Abstract

The invention provides a preparation method of methylene methyldisulfonate, an electrolyte, a battery, a battery pack and electric equipment.The preparation method of the methylene methyldisulfonate comprises the following steps that a mixed material of methyldisulfonic acid, a methylene donor, a solvent and a dehydrating agent reacts to obtain the methylene methyldisulfonate; the solvent comprises an anhydride compound. According to the preparation method provided by the invention, the yield of methylene methyldisulfonate can be effectively improved by limiting part of reaction raw materials as the reaction solvent.

Description

Technical Field

[0001] The invention relates to the technical field of organic chemical synthesis, and in particular to a preparation method of methylene disulfonate, an electrolyte, a battery, a battery pack, and electrical equipment. Background Art

[0002] Methylene disulfonate (MMDS) has a unique disulfonate ring structure in its molecule and can be used as an additive for lithium-ion battery electrolytes. Adding methylene disulfonate to lithium battery electrolytes can greatly improve the high-temperature cycle performance of lithium-ion batteries and extend the service life of lithium batteries.

[0003] At present, methylene disulfonate is mostly produced by organic synthesis, but the existing production process has the defects of complex preparation process, low yield, difficult post-treatment, etc. Therefore, it is necessary to provide a preparation method with simple preparation process and higher yield of methylene disulfonate. Summary of the invention

[0004] The invention provides a preparation method of methylene disulfonate. The preparation method can prepare methylene disulfonate by a one-pot method by limiting part of reaction raw materials and solvents, and ensures a high yield.

[0005] The present invention also provides an electrolyte. Since the electrolyte includes the methylene disulfonate, the electrolyte can improve the high-temperature cycle performance of the lithium-ion battery and extend the service life of the lithium battery.

[0006] The present invention also provides a battery. Since the battery comprises the electrolyte, the battery has excellent high-temperature cycle performance and a long service life.

[0007] The present invention also provides a battery pack, which includes the above-mentioned battery and thus has the advantages of high-temperature cycle stability and a long service life.

[0008] The present invention also provides an electrical device. Since the electrical device comprises the battery or battery pack, the electrical device has good cycle stability and a long service life.

[0009] In detail, in a first aspect, the present invention provides a method for preparing methylene disulfonate, comprising the following steps:

[0010] A mixture of methanedisulfonic acid, a methylene donor, a solvent and a dehydrating agent is reacted at a temperature not lower than 80° C. to obtain the methylene disulfonate; the solvent comprises an anhydride compound shown in Formula 1:

[0011]

[0012] Wherein, R1 and R2 may or may not form a ring. When R1 and R2 do not form a ring, R1 and R2 are each independently any one of a C1-C5 alkyl group, a C3-C6 cycloalkyl group, a phenyl group, a benzyl group, and a phenethyl group;

[0013] When R1 and R2 form a ring, the ring formed by R1 and R2 is any one of a five-membered ring, a six-membered ring, a five-membered ring with a C1-C5 alkyl branch, and a six-membered ring with a C1-C5 alkyl branch.

[0014] Furthermore, when R1 and R2 do not form a ring, R1 and R2 are each independently a C1-C3 alkyl group or a phenyl group; when R1 and R2 form a ring, R1 and R2 form a five-membered ring.

[0015] Furthermore, the acid anhydride compound is selected from at least one of propionic anhydride, maleic anhydride, succinic anhydride, benzoic anhydride and acetic anhydride.

[0016] Furthermore, the structure of the methylene donor is (CH2O)n, wherein 1≤n≤95.

[0017] Furthermore, the dehydrating agent includes at least one of phosphorus pentoxide, phosphorus trichloride, phosphorus oxychloride, phosphorus pentachloride, acetyl chloride, propionyl chloride, butyryl chloride, benzoyl chloride, oxalyl chloride, chloroacetyl chloride, trichloroacetyl chloride, and sulfuryl chloride.

[0018] Furthermore, the solvent also includes at least one of dimethyl sulfoxide, 1,4-dioxane, chloroform, carbon tetrachloride, toluene, and thionyl chloride.

[0019] Further, the mixed material is reacted at a temperature of 80°C-120°C;

[0020] And / or, the percentage of the acid anhydride compound to the total mass of the solvent is m, wherein m≥70%.

[0021] Further, the mass ratio of the methanedisulfonic acid to the solvent is 1:10-30;

[0022] And / or, the molar ratio of the methanedisulfonic acid to the dehydrating agent is 1:1.1-1.5;

[0023] And / or, the molar ratio of the methanedisulfonic acid to the methylene donor is 1:1.1-1.3.

[0024] Furthermore, the method further comprises the step of using thin layer chromatography to monitor the reaction in real time.

[0025] In a second aspect, the present invention provides an electrolyte comprising methylene disulfonate prepared by the preparation method described in the first aspect.

[0026] In a third aspect, the present invention provides a battery, comprising the electrolyte, positive electrode sheet and negative electrode sheet described in the second aspect.

[0027] In a fourth aspect, the present invention provides a battery pack, comprising the battery described in the third aspect.

[0028] In a fifth aspect, the present invention provides an electrical device, comprising the battery described in the third aspect or the battery pack described in the fourth aspect.

[0029] The preparation method of methylene disulfonate provided by the present invention has a simple process, and by limiting some reaction raw materials and solvents, the yield of methylene disulfonate can be improved. Specifically: on the one hand, the acid anhydride compound of the present invention has a high boiling point, so that the reaction system can be allowed to be heated to a higher temperature, which is conducive to the forward reaction, and the reaction yield can be improved and the reaction time can be shortened; on the other hand, the acid anhydride compound of the present invention itself has a certain dehydration property, and when it is used as a solvent, it can also be synergistically dehydrated with other dehydrating agents, thereby improving the efficiency of the ring-closing reaction; on the other hand, the solvent of the present invention has a high adaptability to various reaction substrates, and can effectively dissolve various substances such as raw material methylene disulfonic acid, methylene donor, dehydrating agent and phosphoric acid produced by the reaction, so that the reaction is always kept in a homogeneous phase, and the situation that the by-products wrap the raw materials is avoided, thereby helping to further improve the yield of methylene disulfonate. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0031] Figure 1 It is a gas chromatogram comparison diagram of methylene disulfonate prepared in Example 1 and a methylene disulfonate standard sample;

[0032] Figure 2 This is a TLC detection chart of the reaction solution when the preparation reaction of Example 1 is completed. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below. The specific implementation methods listed below are only for describing the principles and features of the present invention. The examples are only used to explain the present invention and are not intended to limit the scope of the present invention. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0034] Conventional solvents such as chloroalkanes and esters cannot effectively dissolve various reactants and intermediates in the preparation process of methylene disulfonate, resulting in the generated by-products encapsulating the raw materials, preventing the forward reaction from proceeding, and ultimately resulting in a low yield of methylene disulfonate. In view of the above problems, the present invention adopts the following technical solutions:

[0035] In a first aspect, the present invention provides a method for preparing methylene disulfonate, comprising the following steps:

[0036] A mixture of methanedisulfonic acid, a methylene donor, a solvent and a dehydrating agent is reacted at a temperature not lower than 80° C. to obtain the methylene disulfonate; the solvent comprises an anhydride compound shown in Formula 1:

[0037]

[0038] Wherein, R1 and R2 may or may not form a ring. When R1 and R2 do not form a ring, R1 and R2 are each independently any one of a C1-C5 alkyl group, a C3-C6 cycloalkyl group, a phenyl group, a benzyl group, and a phenethyl group;

[0039] When R1 and R2 form a ring, the ring formed by R1 and R2 is any one of a five-membered ring, a six-membered ring, a five-membered ring with a C1-C5 alkyl branch, and a six-membered ring with a C1-C5 alkyl branch.

[0040] In the present invention, by limiting some reaction raw materials and solvents, the selectivity and yield of methylene disulfonate can be effectively improved. In detail: on the one hand, the acid anhydride compound of the present invention has a high boiling point, so that the reaction system can be allowed to be heated to a higher temperature, which is conducive to the forward reaction, and the reaction yield can be improved and the reaction time can be shortened; on the other hand, the acid anhydride compound of the present invention itself has a certain dehydration property, and when it is used as a solvent, it can also be synergistically dehydrated with other dehydrating agents, thereby improving the efficiency of the ring-closing reaction; on the other hand, the solvent of the present invention has a high adaptability to various reaction substrates, and can effectively dissolve various reaction substrates, such as raw material methylene disulfonic acid, methylene donor, dehydrating agent, and phosphoric acid produced by the reaction, etc., under the condition of not less than 80°C, so that the reaction is always kept in a homogeneous phase, avoiding the situation where the by-products wrap the raw materials, thereby helping to further improve the yield of methylene disulfonate.

[0041] In a specific embodiment, when R1 and R2 do not form a ring, R1 and R2 are each independently a C1-C3 alkyl group or a phenyl group; when R1 and R2 form a ring, R1 and R2 form a five-membered ring.

[0042] In another specific embodiment, the acid anhydride compound is selected from at least one of propionic anhydride, maleic anhydride, succinic anhydride, benzoic anhydride and acetic anhydride. The acid anhydride compound of this embodiment has lower cost and better dehydration effect of the synergistic dehydrating agent, which helps to further improve the yield of methylene disulfonate.

[0043] In one specific embodiment, the structure of the methylene donor is (CH2O)n, wherein 1≤n≤95.

[0044] Exemplarily, the methylene donor may be formaldehyde gas, trioxymethylene, tetraoxymethylene, polyoxymethylene (degree of polymerization n=92), or polyoxymethylene (degree of polymerization n=95).

[0045] In a specific embodiment, the dehydrating agent includes at least one of phosphorus pentoxide, phosphorus trichloride, phosphorus oxychloride, phosphorus pentachloride, acetyl chloride, propionyl chloride, butyryl chloride, benzoyl chloride, oxalyl chloride, chloroacetyl chloride, trichloroacetyl chloride, and sulfuryl chloride.

[0046] In order to further exert the synergistic effect of the acid anhydride compound and the dehydrating agent, preferably, the dehydrating agent includes at least one of acetyl chloride, propionyl chloride, butyryl chloride, benzoyl chloride, oxalyl chloride, chloroacetyl chloride, trichloroacetyl chloride and sulfuryl chloride.

[0047] In order to further reduce the cost, in a specific embodiment, the solvent further comprises: at least one of dimethyl sulfoxide, 1,4-dioxane, chloroform, carbon tetrachloride, toluene, and thionyl chloride.

[0048] The specific temperature of the reaction is not particularly limited in the present invention, and the technician can adjust it according to the reaction rate. In order to speed up the reaction rate, in a specific embodiment, the mixed material is reacted at a temperature of 80° C.-120° C.;

[0049] Since the reaction raw materials and / or products contain gas, in some embodiments, the reaction is carried out in a closed container, and the pressure during the reaction is 0.1Mpa-10Mpa. Exemplarily, the reaction temperature is 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, etc.

[0050] In order to better exert the solubility and synergistic dehydration effect of the acid anhydride compounds, in a specific embodiment, the percentage of the acid anhydride compounds to the total mass of the solvent is m, wherein m≥70%.

[0051] Among them, the amount of solvent added will change the concentration of the reactants. When the amount of solvent added relative to methyl disulfonic acid increases, the concentration of methyl disulfonic acid will decrease relatively, thereby possibly slowing down the reaction rate. Conversely, if the amount of solvent added relative to methyl disulfonic acid decreases, the concentration of methyl disulfonic acid increases, which may accelerate the reaction rate. In order to balance the relationship between the reaction rate and the process cost, in a specific embodiment, the mass ratio of the methyl disulfonic acid to the solvent is 1:10-30; and when the amount of the dehydrating agent added relative to the methyl disulfonic acid is too high, the viscosity of the reaction system may be too large, affecting the reaction rate. When the amount of methyl disulfonic acid added is too low, the efficiency of the ring-closing reaction is reduced, affecting the yield of the target product. Therefore, in order to balance the reaction rate and the yield of the target product, in a specific embodiment, the molar ratio of the methyl disulfonic acid to the dehydrating agent is 1:1.1-1.5; further, to balance the relationship between the reaction rate and the process cost, in another specific embodiment, the molar ratio of the methyl disulfonic acid to the methylene donor is 1:1.1-1.3.

[0052] In one embodiment, the step of real-time monitoring of the reaction using thin layer chromatography is further included.

[0053] In the process of synthesizing methylene disulfonate, if the reaction degree is not monitored, the reaction time cannot be accurately controlled, and the by-products will increase if the reaction is overtime, thereby reducing the final yield of the target product; therefore, the above-mentioned embodiment uses thin layer chromatography (TLC) for real-time tracking and monitoring of the reaction, which can not only effectively control the reaction time, but also help to improve the yield of the target product.

[0054] In a specific embodiment, the developing solvent system used in the thin layer chromatography method consists of one or two of petroleum ether, ethyl acetate, n-hexane, dichloromethane, chloroform, methanol, and water; further, it is a mixture of ethyl acetate and petroleum ether in a volume ratio of 1:5, and / or, the thin layer chromatography method uses an iodine cylinder for color development.

[0055] Exemplarily, the developer of the iodine cylinder color development is composed of iodine and silica gel, the particle size of the silica gel is selected from one or more of 100 mesh, 200 mesh, 300 mesh, 400 mesh, and 500 mesh; the mass ratio of iodine to silica gel is 1:5-20; and the iodine cylinder fumigation time is 1 min-10 min.

[0056] In a second aspect, the present invention provides an electrolyte comprising methylene disulfonate prepared by the preparation method described in the first aspect.

[0057] The electrolyte also includes an organic solvent, and the organic solvent includes at least one of ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), butylene carbonate (BC), fluoroethylene carbonate (FEC), methyl formate (MF), methyl acetate (MA), ethyl acetate (EA), propyl acetate (PA), methyl propionate (MP), ethyl propionate (EP), propyl propionate (PP), methyl butyrate (MB), ethyl butyrate (EB), 1,4-butyrolactone (GBL), cyclopentane (SF), dimethyl sulfone (MSM), ethyl methyl sulfone (EMS), and diethyl sulfone (ESE).

[0058] In a specific embodiment, the electrolyte also includes a lithium salt, and the lithium salt includes at least one of lithium hexafluorophosphate, lithium hexafluoroarsenate, lithium tetrafluoroborate, lithium difluorooxalatoborate, lithium difluorobisoxalatephosphate, lithium tetrafluorooxalatephosphate, lithium bis(trifluoromethanesulfonyl)imide, lithium perfluorobutylsulfonate and lithium fluorinated fatty acid.

[0059] The mass proportion of the above-mentioned lithium salt in the electrolyte is not particularly limited in the present invention, and technicians can adjust it according to actual conditions. However, in order for the lithium salt to be dissolved in the organic solvent to form an electrolyte with high stability and good lithium conductivity, and at the same time to make the viscosity of the electrolyte appropriate, in some embodiments, the mass proportion of the lithium salt in the electrolyte is 6wt%-25wt%.

[0060] Exemplarily, the mass percentage of the non-aqueous organic solvent is 60wt%-92wt%, preferably 65wt%-85wt%. When the organic solvent is within the above range, the lithium salt can be fully dissolved in the electrolyte, which helps to prepare an electrolyte with high conductivity and strong stability, so that the electrochemical performance of the battery is stable.

[0061] In a third aspect, the present invention provides a battery, comprising the electrolyte, positive electrode sheet and negative electrode sheet described in the second aspect.

[0062] The positive electrode sheet includes a positive electrode active material, which includes but is not limited to LiCoO2, LiMn2O4, LiMnO2, Li2MnO4, LiFePO4, Li 1+a Mn 1-b M b O2、LiCo 1-b M b O2、LiFe 1-b M b PO4、Li2Mn 1-b O4、LiNi x Coy Mn z At least one of O2, etc., M is selected from one or more of Ni, Co, Mn, Al, Cr, Mg, Zr, Mo, V, Ti, B, F, 0≤a<0.2, 0≤b<1, x+y+z=1.

[0063] Furthermore, the positive electrode active materials include but are not limited to LiCoO2, LiFeMnPO4, LiNi 0.6 Co 0.2 Mn 0.2 O2、LiNi 0.5 Co 0.2 Mn 0.3 O2、LiNi 0.8 Co 0.1 Mn 0.1 O2, etc.

[0064] The negative electrode sheet includes a negative electrode active material, which may be a conventional material in the art, including but not limited to one or more of carbonaceous materials, silicon-carbon materials, alloy materials, and lithium-containing metal composite oxides. Furthermore, the negative electrode active material is one or more of graphite, soft carbon, hard carbon, silicon, silicon-oxygen compounds, silicon-carbon composites, and lithium titanate.

[0065] The battery may further include a diaphragm, and the material of the diaphragm may be selected by technicians from conventional diaphragms, such as polyolefin, aromatic polyamide, polytetrafluoroethylene, polyethersulfone, and the like.

[0066] In a fourth aspect, the present invention provides a battery pack, comprising the battery described in the third aspect.

[0067] In a fifth aspect, the present invention provides an electrical device, comprising the battery described in the third aspect or the battery pack described in the fourth aspect.

[0068] It should be noted that the above-mentioned electrical equipment can be any conventional equipment that requires electricity, for example, including but not limited to computers, electric cars, air conditioners, refrigerators, washing machines, microwave ovens, printers, fax machines, etc.

[0069] The present invention is further described below in conjunction with specific embodiments:

[0070] Example 1

[0071] This example provides a method for preparing methylene disulfonate, comprising the following steps:

[0072] 1) Preparation of developing agent and color developer: Use a 25 mL measuring cylinder to measure 4 mL of ethyl acetate and 50 mL of petroleum ether, respectively, mix to obtain a MMDS developing agent (ethyl acetate / petroleum ether, V / V) with a volume ratio of 1:5 for later use. Weigh 5 g of iodine and 50 g of silica gel (200 mesh) respectively, put them into a 500 mL brown wide-mouth bottle and mix them evenly for later use.

[0073] 2) At room temperature, 8.8 g (0.05 mol, 1 eq) of methanedisulfonic acid, 176 g (1.35 mol, 27 eq) of propionic anhydride, 4.71 g (0.06 mol, 1.2 eq) of acetyl chloride, and 1.8 g (0.06 mol, 1.2 eq; degree of polymerization = 95) of paraformaldehyde were added in sequence to a 500 mL four-necked flask equipped with a stirrer, a thermometer, a reflux tube, and an exhaust gas treatment device. After the addition was completed, the mixture was placed in an oil bath at 110° C. for reaction for 5 h. The reaction system changed from the initial light yellow to a dark brown solution. From the start of the reaction, a small amount of the reaction solution was taken with a long needle for TLC monitoring every 1 h until the methanedisulfonic acid raw material point completely disappeared. Turn off the heating, cool the system to 30-40°C, slowly introduce the reaction solution into 200 mL of ice water for quenching, stir for 0.5 h, extract with ethyl acetate (150 mL×3), wash with saturated brine (50 mL×3), remove excess acetyl chloride, combine the organic phases, add 40 g of anhydrous sodium sulfate for drying, distill under reduced pressure, separate by column chromatography (elute with 250 mL of pure petroleum ether, then with 500 mL of a mixed solvent consisting of ethyl acetate and petroleum ether in a volume of 1:5), monitor the MMDS product point by TLC, combine the organic phases, distill under reduced pressure, and dry in vacuo to obtain 6.7 g of methylene disulfonate as white crystals with a yield of 72%.

[0074] The prepared samples and MMDS standard samples were subjected to gas chromatography (GC) comparative analysis using the same method (column model: DB-1301 20°C ~ 280°C (300°C); 30m×250μm×0.25μm; detector temperature 280°C. The results showed that the retention time of the prepared sample and the methylene disulfonic acid standard sample was 15.44min.

[0075] Example 2

[0076] This example provides a method for preparing methylene disulfonate, comprising the following steps:

[0077] 1) Preparation of developing agent and color developer: Use a 25 mL measuring cylinder to measure 4 mL of ethyl acetate and 50 mL of petroleum ether, respectively, and mix them to obtain a MMDS developing agent (ethyl acetate / petroleum ether, V / V) with a volume ratio of 1:5 for use; weigh 5 g of iodine and 50 g of silica gel (200 mesh) respectively, put them into a 500 mL brown wide-mouth bottle and mix them evenly for use.

[0078] 2) At room temperature, 8.8 g (0.05 mol, 1 eq) of methanedisulfonic acid, 176 g (1.35 mol, 27 eq) of propionic anhydride, 7.81 g (0.055 mol, 1.1 eq) of phosphorus pentoxide, and 1.8 g (0.06 mol, 1.2 eq; degree of polymerization = 95) of paraformaldehyde were added in sequence to a 500 mL four-necked flask equipped with a stirrer, a thermometer, and a reflux tube. After the addition was completed, the mixture was placed in an oil bath at 110°C for reaction for 5 h. The reaction system changed from the initial light yellow to a black solution. From the start of the reaction, a small amount of the reaction solution was taken with a long needle for TLC monitoring every 1 h until the methanedisulfonic acid raw material point completely disappeared, and the heating was turned off. , the system was cooled to 30-40°C, the reaction solution was slowly introduced into 200 mL of ice water for quenching, stirred for 0.5 h, excess phosphorus pentoxide was removed, extracted with ethyl acetate (150 mL × 3), washed with saturated brine (50 mL × 3), the organic phases were combined, 30 g of anhydrous sodium sulfate was added for drying, distilled under reduced pressure, separated by column chromatography (eluted with 250 mL of pure petroleum ether, then eluted with 500 mL of a mixed solvent, the mixed solvent consisting of ethyl acetate and petroleum ether in a volume of 1:5), TLC monitored the MMDS product point, the organic phases were combined, distilled under reduced pressure, and dried in vacuo to obtain 7.9 g of methylene disulfonate as white crystals with a yield of 84%.

[0079] The prepared samples and MMDS standard samples were subjected to gas chromatography (GC) comparative analysis using the same method (column model: DB-1301 20°C ~ 280°C (300°C); 30m×250μm×0.25μm; detector temperature 280°C; the results showed that the retention time of the prepared sample and the methylene disulfonic acid standard sample was 15.44min.

[0080] Example 3

[0081] This example provides a method for preparing methylene disulfonate, comprising the following steps:

[0082] 1) Preparation of developing agent and color developer: Use a 25 mL measuring cylinder to measure 4 mL of ethyl acetate and 50 mL of petroleum ether, respectively, and mix them to obtain a MMDS developing agent (ethyl acetate / petroleum ether, V / V) with a volume ratio of 1:5 for use; weigh 5 g of iodine and 50 g of silica gel (200 mesh) respectively, put them into a 500 mL brown wide-mouth bottle and mix them evenly for use.

[0083] 2) At room temperature, 8.8 g (0.05 mol, 1 eq) of methanedisulfonic acid, 176 g (1.35 mol, 27 eq) of propionic anhydride, 11.44 g (0.055 mol, 1.1 eq) of phosphorus pentachloride, and 1.8 g (0.06 mol, 1.2 eq; degree of polymerization = 95) of paraformaldehyde were added in sequence to a 500 mL four-necked flask equipped with a stirrer, a thermometer, a reflux tube, and an exhaust gas treatment device. After the addition was completed, the mixture was placed in an oil bath at 110° C. for reaction for 5 h. The reaction system changed from the initial light yellow to a black solution. From the start of the reaction, a small amount of the reaction solution was taken with a long needle for TLC monitoring every 1 h until the methanedisulfonic acid raw material point completely disappeared. Turn off the heating, cool the system to 30-40°C, slowly drip the reaction solution into 200 mL of ice water to quench, stir for 0.5 h, extract with ethyl acetate (150 mL×3), wash with saturated brine (50 mL×3), remove excess phosphorus pentachloride, combine the organic phases, add 40 g of anhydrous sodium sulfate to dry, distill under reduced pressure, separate by column chromatography (elute with 250 mL of pure petroleum ether, then elute with 500 mL of a mixed solvent consisting of ethyl acetate and petroleum ether in a volume of 1:5), monitor the MMDS product point by TLC, combine the organic phases, distill under reduced pressure, and dry in vacuo to obtain 7.1 g of methylene disulfonate as white crystals with a yield of 77%.

[0084] The above samples and MMDS standard samples were subjected to gas chromatography (GC) comparative analysis using the same method (column model: DB-1301 20°C ~ 280°C (300°C); 30m×250μm×0.25μm; detector temperature 280°C. The results showed that the retention time of the prepared sample and the methylene disulfonic acid standard sample was 15.44min.

[0085] Example 4

[0086] This example provides a method for preparing methylene disulfonate, comprising the following steps:

[0087] 1) Preparation of developing agent and color developer: Use a 25 mL measuring cylinder to measure 4 mL of ethyl acetate and 50 mL of petroleum ether, respectively, and mix them to obtain a MMDS developing agent (ethyl acetate / petroleum ether, V / V) with a volume ratio of 1:5 for use; weigh 5 g of iodine and 50 g of silica gel (200 mesh) respectively, put them into a 500 mL brown wide-mouth bottle and mix them evenly for use.

[0088] 2) At room temperature, 8.8 g (0.05 mol, 1 eq) of methyl disulfonic acid, 176 g (1.35 mol, 27 eq) of propionic anhydride, 6.54 g (0.055 mol, 1.1 eq) of thionyl chloride, and 1.8 g (0.06 mol, 1.2 eq) of trioxymethylene were added in sequence to a 500 mL four-necked flask equipped with a stirrer, a thermometer, a reflux tube, and an exhaust gas treatment device. After the addition was completed, the mixture was placed in an oil bath at 110°C for reaction for 5 h. The reaction system changed from the initial light yellow to a brown solution. From the start of the reaction, a small amount of the reaction solution was taken with a long needle for TLC monitoring every 1 h until the methyl disulfonic acid raw material point completely disappeared, and the heating was turned off. , the system was cooled to 30-40°C, the reaction solution was slowly dripped into 200 mL of ice water to quench, stirred for 0.5 h, excess thionyl chloride was removed, extracted with ethyl acetate (150 mL×3), washed with saturated brine (50 mL×3), the organic phases were combined, 40 g of anhydrous sodium sulfate was added and dried, distilled under reduced pressure, separated by column chromatography (eluted with 250 mL of pure petroleum ether, then eluted with 500 mL of a mixed solvent, the mixed solvent consisted of ethyl acetate and petroleum ether in a volume of 1:5), TLC monitored the MMDS product point, the organic phases were combined, distilled under reduced pressure, and dried in vacuo to obtain 7.5 g of methylene disulfonate as white crystals with a yield of 81%.

[0089] The prepared samples and MMDS standard samples were subjected to gas chromatography (GC) comparative analysis using the same method (column model: DB-1301 20°C ~ 280°C (30°C); 30m×250μm×0.25μm; detector temperature 280°C. The results showed that the retention time of the prepared samples and the methylene disulfonic acid standard sample was 15.4min.

[0090] Example 5

[0091] This example provides a method for preparing methylene disulfonate, comprising the following steps:

[0092] 1) Preparation of developing agent and color developer: Use a 25 mL measuring cylinder to measure 4 mL of ethyl acetate and 50 mL of petroleum ether, respectively, and mix them to obtain a MMDS developing agent (ethyl acetate / petroleum ether, V / V) with a volume ratio of 1:5 for use; weigh 5 g of iodine and 50 g of silica gel (200 mesh) respectively, put them into a 500 mL brown wide-mouth bottle and mix them evenly for use.

[0093] 2) At room temperature, 8.8 g (0.05 mol, 1 eq) of methanedisulfonic acid, 213.5 g (1.35 mol, 27 eq) of butyric anhydride, 5.1 g (0.055 mol, 1.1 eq) of propionyl chloride, and 1.8 g (0.06 mol, 1.2 eq; degree of polymerization = 95) of paraformaldehyde were added in sequence into a 500 mL four-necked flask equipped with a stirrer, a thermometer, a reflux tube, and an exhaust gas treatment device. After the addition was completed, the mixture was placed in an oil bath at 110° C. for reaction for 5 h. The reaction system changed from the initial light yellow to a brown solution. From the start of the reaction, a small amount of the reaction solution was taken with a long needle for TLC monitoring every 0.5 h until the methanedisulfonic acid raw material point completely disappeared. , turn off the heating, cool the system to 30-40°C, slowly drop the reaction solution into 200 mL of ice water to quench, stir for 0.5 h, remove excess thionyl chloride, extract with ethyl acetate (150 mL×3), wash with saturated brine (50 mL×3), combine the organic phases, add 40 g of anhydrous sodium sulfate to dry, distill under reduced pressure, separate by column chromatography (elute with 250 mL of pure petroleum ether, then elute with 500 mL of a mixed solvent, the mixed solvent consists of ethyl acetate and petroleum ether in a volume of 1:5), monitor the MMDS product point by TLC, combine the organic phases, distill under reduced pressure, and dry in vacuo to obtain 7.7 g of methylene disulfonate as white crystals with a yield of 82%.

[0094] The prepared samples and MMDS standard samples were subjected to gas chromatography (GC) comparative analysis using the same method (column model: DB-1301 20°C ~ 280°C (30°C); 30m×250μm×0.25μm; detector temperature 280°C. The results showed that the retention time of the prepared samples and the methylene disulfonic acid standard sample was 15.4min.

[0095] Example 6

[0096] This example provides a method for preparing methylene disulfonate, comprising the following steps:

[0097] 1) Preparation of developing agent and color developer: Use a 25 mL measuring cylinder to measure 4 mL of ethyl acetate and 50 mL of petroleum ether, respectively, and mix them to obtain a MMDS developing agent (ethyl acetate / petroleum ether, V / V) with a volume ratio of 1:5 for use; weigh 5 g of iodine and 50 g of silica gel (200 mesh) respectively, put them into a 500 mL brown wide-mouth bottle and mix them evenly for use.

[0098] 2) At room temperature, 8.8 g (0.05 mol, 1 eq) of methanedisulfonic acid, 213.5 g (1.35 mol, 27 eq) of butyric anhydride, 5.9 g (0.055 mol, 1.1 eq) of n-butyryl chloride, and 1.8 g (0.06 mol, 1.2 eq; degree of polymerization = 95) of paraformaldehyde were added in sequence into a 500 mL four-necked flask equipped with a stirrer, a thermometer, a reflux tube, and an exhaust gas treatment device. After the addition was completed, the mixture was placed in an oil bath at 110° C. for reaction for 5 h. The reaction system changed from the initial light yellow to a brown solution. From the start of the reaction, a small amount of the reaction solution was taken with a long needle for TLC monitoring every 0.5 h until the methanedisulfonic acid raw material point completely disappeared. , turn off the heating, cool the system to 30-40°C, slowly drip the reaction solution into 200 mL of ice water to quench, stir for 0.5 h, remove excess thionyl chloride, extract with ethyl acetate (150 mL×3), wash with saturated brine (50 mL×3), combine the organic phases, add 40 g of anhydrous sodium sulfate and dry, distill under reduced pressure, separate by column chromatography (elute with 250 mL of pure petroleum ether, then elute with 500 mL of a mixed solvent, the mixed solvent consists of ethyl acetate and petroleum ether in a volume of 1:5), monitor the MMDS product point by TLC, combine the organic phases, distill under reduced pressure, and dry in vacuo to obtain 7.52 g of methylene disulfonate as white crystals with a yield of 80%.

[0099] The prepared samples and MMDS standard samples were subjected to gas chromatography (GC) comparative analysis using the same method (column model: DB-1301 20°C ~ 280°C (30°C); 30m×250μm×0.25μm; detector temperature 280°C. The results showed that the retention time of the prepared samples and the methylene disulfonic acid standard sample was 15.4min.

[0100] Comparative Example 1

[0101] This example provides a method for preparing methylene disulfonate, comprising the following steps:

[0102] In a 500mL three-necked flask equipped with a stirrer, a condenser, and a thermometer, 8.8g (0.05mol, 1eq) of 1,2-dimethylsulfonic acid and 1,2-dichloroethane (50mL) were first added, followed by 8.5g (0.06mol, 1.2eq) of phosphorus pentoxide and 2g (0.06mol, 1.2eq) of paraformaldehyde (degree of polymerization = 95). After the addition was completed, nitrogen was replaced three times, and the mixture was placed in an oil bath at 110°C and refluxed for 5h. When the reaction is completed, the upper dichloroethane solvent phase is clear and the bottom of the flask is a black viscous substance; the reaction system is allowed to stand and cool to room temperature, 100 mL of dichloromethane is added to dilute the reaction solution, ultrasonicated for 3 minutes, filtered, and then 30 g of anhydrous sodium sulfate is added to dry the filtrate, followed by 5 g of activated carbon (200 mesh) for decolorization, stirred for 5 minutes, allowed to stand for 1 hour, filtered, and the collected filtrate is dried under low-temperature vacuum to obtain 4.5 g of methylene disulfonate as white crystals with a yield of 48%.

[0103] The prepared samples and MMDS standard samples were subjected to gas chromatography (GC) comparative analysis using the same method (column model: DB-1301 20°C ~ 280°C (300°C); 30m×250μm×0.25μm; detector temperature 280°C; the results showed that the retention time of the prepared sample and the methylene disulfonic acid standard sample was 15.44min.

[0104] Comparative Example 2

[0105] This example provides a method for preparing methylene disulfonate, comprising the following steps:

[0106] In a 500mL three-necked flask equipped with a stirrer, a condenser, and a thermometer, 8.8g (0.05mol, 1eq) of 1,2-dimethylsulfonic acid and 50mL of diethyl carbonate were first added, followed by 8.5g (0.06mol, 1.2eq) of phosphorus pentoxide and 2g (0.06mol, 1.2eq) of paraformaldehyde (degree of polymerization = 95) in sequence. After the addition was completed, nitrogen was replaced three times, and the mixture was placed in an oil bath at 110°C and refluxed for 5h. The reaction solution was observed to change from white turbidity to black turbidity. TLC indicated that the reaction was complete. The upper diethyl carbonate solvent phase is clear, and the bottom of the flask is a black viscous substance; the reaction system is allowed to stand and cool to room temperature, 100 mL of ethyl acetate is added to dilute the reaction solution, ultrasonicated for 3 minutes, filtered, and then 30 g of anhydrous sodium sulfate is added to dry the filtrate, followed by 5 g of activated carbon (200 mesh) for decolorization, stirred for 5 minutes, allowed to stand for 1 hour, filtered, and a yellow oily product was collected. The product was separated by column chromatography, and the organic phases were collected and combined, distilled under reduced pressure, and dried in vacuo for 5 hours to obtain 4.2 g of methylene disulfonate as white crystals with a yield of 45%.

[0107] The prepared samples and MMDS standard samples were subjected to gas chromatography (GC) comparative analysis using the same method (column model: DB-1301 20°C ~ 280°C (300°C); 30m×250μm×0.25μm; detector temperature 280°C; the results showed that the retention time of the prepared sample and the methanedisulfonic acid standard sample was 15.44min.

[0108] Comparative Example 3

[0109] The same as Comparative Example 1, the only difference is that the solvent is 1,2-dichloroethane.

[0110] Comparative Example 4

[0111] Same as Comparative Example 2, except that the dehydrating agent is acetyl chloride.

[0112] Some reaction conditions of the examples and comparative examples and the yields of methylene disulfonate are summarized in Table 1; wherein the following calculation formula for the yield is: yield = theoretical product mass (g) / actual product mass (g) × 100%.

[0113] Table 1:

[0114]

[0115]

[0116] It can be seen from Table 1 that, compared with the comparative example, the preparation method of the embodiment can significantly improve the yield of methylene disulfonate.

[0117] 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 it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing methylene disulfonate, characterized in that: The steps include: A mixture of methanedisulfonic acid, a methylene donor, a solvent and a dehydrating agent is reacted at a temperature not lower than 80° C. to obtain the methylene disulfonate; the solvent comprises an anhydride compound shown in Formula 1: Wherein, R1 and R2 may or may not form a ring. When R1 and R2 do not form a ring, R1 and R2 are each independently any one of a C1-C5 alkyl group, a C3-C6 cycloalkyl group, a phenyl group, a benzyl group, and a phenethyl group. When R1 and R2 form a ring, the ring formed by R1 and R2 is any one of a five-membered ring, a six-membered ring, a five-membered ring with a C1-C5 alkyl side chain, and a six-membered ring with a C1-C5 alkyl side chain.

2. The preparation method according to claim 1, characterized in that: When R1 and R2 do not form a ring, R1 and R2 are each independently a C1-C3 alkyl group or a phenyl group. When R1 and R2 form a ring, R1 and R2 form a five-membered ring.

3. The preparation method according to claim 1 or 2, characterized in that: The acid anhydride compound is selected from at least one of propionic anhydride, maleic anhydride, succinic anhydride, benzoic anhydride and acetic anhydride.

4. The preparation method according to any one of claims 1 to 3, characterized in that: The structure of the methylene donor is (CH2O)n, wherein 1≤n≤95.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The dehydrating agent comprises at least one of phosphorus pentoxide, phosphorus trichloride, phosphorus oxychloride, phosphorus pentachloride, acetyl chloride, propionyl chloride, butyryl chloride, benzoyl chloride, oxalyl chloride, chloroacetyl chloride, trichloroacetyl chloride and sulfuryl chloride.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The solvent further comprises: at least one of dimethyl sulfoxide, 1,4-dioxane, chloroform, carbon tetrachloride, toluene and thionyl chloride.

7. The preparation method according to any one of claims 1 to 5, characterized in that: The mixed material is reacted at a temperature of 80° C.-120° C.; and / or the percentage of the acid anhydride compound to the total mass of the solvent is m, wherein m≥70%.

8. The preparation method according to claim 7, characterized in that: The mass ratio of the methanedisulfonic acid to the solvent is 1:10-30; And / or, the molar ratio of the methanedisulfonic acid to the dehydrating agent is 1:1.1-1.5; And / or, the molar ratio of the methanedisulfonic acid to the methylene donor is 1:1.1-1.

3.

9. The preparation method according to any one of claims 1 to 8, characterized in that: Also included is the step of monitoring the reaction in real time using thin layer chromatography.

10. An electrolyte, characterized in that: The invention comprises methylene disulfonate prepared by any one of the preparation methods of claims 1 to 9.

11. A battery, characterized in that: It comprises the electrolyte, positive electrode sheet and negative electrode sheet as claimed in claim 10.

12. A battery pack, characterized in that: Comprising the battery of claim 11.

13. An electrical equipment, characterized in that: Comprising the battery according to claim 11 or the battery pack according to claim 12.

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