87 results about "Diethyl carbonate" patented technology

The application belongs to the technical field of regenerated polyester, and particularly relates to a recycling method of waste polyester textiles, which comprises the following steps: decolorizing colored waste polyester textiles by using a decolorizing agent, wherein the decolorizing agent is one or more of dimethyl carbonate, diethyl carbonate and methyl ethyl carbonate; depolymerizing the decolorized polyester textiles by using a depolymerizing agent to obtain terephthalate, wherein the depolymerization rate of the decolorized polyester textiles is 98.0-100%; converting the terephthalate into DMT first, and then performing a re-polymerization reaction on the DMT, ethylene glycol, a catalyst and a functional additive to obtain regenerated PET. The application adopts a process of decolorizing first and then depolymerizing, and the decolorizing and depolymerizing are coordinated, so that the process is simplified, the energy consumption and pollution are reduced, and the economy and sustainability of the recycling of waste polyester textiles are improved.

This invention relates to the field of fine chemical technology, specifically disclosing a production process for electronic-grade diethyl carbonate. The method includes the following steps: ethylene carbonate and anhydrous ethanol undergo a transesterification reaction in a microwave reactor catalyzed by a composite catalyst; the reaction solution is then subjected to phase separation treatment, followed by a continuous separation process coupling atmospheric and vacuum distillation to obtain an intermediate; further purification is achieved by molecular sieve adsorption to remove metal impurities and moisture, combined with precision filtration using a polytetrafluoroethylene membrane. The composite catalyst significantly improves the transesterification reaction efficiency and product selectivity. This process, through the synergistic effect of reaction process enhancement and multi-stage purification technology, achieves highly efficient removal of moisture, metal impurities, and nanoscale particles from the reaction system. The resulting electronic-grade diethyl carbonate meets the stringent requirements of high-end electronic chemicals such as lithium battery electrolytes, and possesses technical advantages such as short reaction cycle, thorough impurity removal, and high product purity.

Disclosed is a preparation method for cannflavin compounds. The preparation method has the advantages of cheap and easily available raw materials, few reaction steps, short production period, simple operation, etc. The method comprises: firstly, condensing 4′-hydroxy-3′-methoxyacetophenone and diethyl carbonate (DEC) under an alkaline condition to obtain 4′-hydroxy-3′-methoxybenzoyl acetate; reacting 1,3,5-trihydroxybenzene with bromo-isoamylene under an alkaline condition to obtain 2-isopentenyl-1,3,5-trihydroxybenzene; and finally, condensing 4′-hydroxy-3′-methoxybenzoyl acetate and 2-isopentenyl-1,3,5-trihydroxybenzene at a high temperature to produce cannflavin B and / or isocannflavin B, and then subjecting same to separation and purification to obtain pure cannflavin B and pure isocannflavin B.

Carbonate compounds are excellent additives of oxygen-containing fuel, and play an important role in improving the oxygen content of fuel. The present application mainly relates to a preparation method of a catalyst for synthesizing carbonate additives. The catalyst is used for catalyzing the preparation of a mixture of methyl ethyl carbonate and diethyl carbonate by means of an ester exchange reaction with dimethyl carbonate and ethanol as raw materials. The mixture obtained after the reaction is used as an oxygen-containing fuel additive. The catalyst is characterized in that the catalyst is a high-efficiency ester exchange catalyst with a multistage-pore ZSM-5 molecular sieve as a carrier, a double-molecule as a connecting agent and an alcohol salt as an active component. In the preparation process of the catalyst, the connecting agent is added. The connecting agent has the advantages of increasing the stability of the sodium alcoholate active component and increasing the loading capacity by using a molecular connecting agent with multiple active groups. The performance of the catalyst is evaluated by using a tank reactor, and the stability of the prepared catalyst in the ester exchange reaction is investigated. The performance evaluation shows that the catalyst prepared by using the connecting agent has higher product yield and more excellent product yield. This has important significance for improving the combustion performance of the oxygen-containing fuel and reducing the fuel cost.

The invention relates to the technical field of synthesis of high molecular material sulfone polymers, in particular to a halogen-free environment-friendly end-capping reagent and a method for carrying out end capping on sulfone polymers by using the halogen-free environment-friendly end-capping reagent. At least one halogen-free environment-friendly end-capping reagent selected from methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, trimethyl carbonate, propylene carbonate and ethylene carbonate is introduced; and at least one ionic liquid selected from the group consisting of 1-ethyl-3-methylimidazole acetate, 1-ethyl-3-methylimidazole methane sulfonate, tetrabutylammonium p-toluenesulfonate and choline acetate is used as a catalyst. According to the method, the problems of environmental pollution and toxic residues caused by a traditional halogen end-capping reagent are effectively avoided. The invention also keeps the bisphenol monomer slightly excessive. And the prepared polysulfone resin has the advantages of obviously enhanced terminal group stability, pure color, high transparency and low chlorine content, and is suitable for the high value-added application fields of medical instruments, food contact materials, electronic devices and the like.

The invention discloses a wide-temperature-range electrolyte and application thereof, and belongs to the technical field of supercapacitors. The wide-temperature-range electrolyte comprises the following components in percentage by mass: 12.5%-15% of lithium salt, 0.3%-1% of [2, 2 '-dinaphthalene]-7-yl trifluoromethanesulfonate, 0.5%-1.5% of a sulfur additive, 0.5%-1% of a lithium salt additive and the balance of an organic solvent, by taking the total volume of the organic solvent as 100%, the volume ratio of the 2-bromo-5-fluoroisonicotinic acid methyl ester to the total volume of the ethylene carbonate and the propylene carbonate to the diethyl carbonate to the ethyl methyl carbonate is (5-10): (10-15): (10-20): (50-65). Experiments prove that by adding the methyl 2-bromo-5-fluoroisonicotinate and the functional [2, 2 '-dinaphthalene]-7-yl trifluoromethanesulfonate into the electrolyte, the high and low temperature discharge performance, especially the low temperature performance, of the supercapacitor can be remarkably improved, and the highest discharge capacity retention rate at-20 DEG C is 84.5%. Therefore, the wide-temperature-range electrolyte prepared by the method can solve the problem that a traditional supercapacitor electrolyte is difficult to consider high and low temperature performance at the same time.

The invention belongs to the technical field of materials, and provides an electrolyte for a high-capacity spinel positive electrode lithium ion battery, a preparation method of the electrolyte and the lithium ion battery. The electrolyte comprises a lithium salt and a carbonic ester mixed solvent, and the mixed solvent is composed of ethylene carbonate, diethyl carbonate, (2, 2, 2-trifluoroethyl) ethyl carbonate and bis (2, 2, 2-trifluoroethyl) carbonate. According to the invention, the combination of solvents is regulated and controlled, a high-inertia fluorinated structure on one side of a molecule and a non-fluorinated structure for promoting solvation on the other side of the molecule are innovatively combined, and the combination of asymmetric and symmetric fluorinated solvents is adopted, so that the advantages of high stability of a fluorinated electrolyte and strong solvation and ionic conduction of a non-fluorinated electrolyte are integrated, and the limitation of the fluorinated electrolyte and the non-fluorinated electrolyte is made up. The electrolyte adapts to a high-low voltage interface charging and discharging process, is well matched with a spinel positive electrode, and can be matched with the circulation interface characteristic, so that the super-theoretical capacity circulation is realized, the energy density is improved, the service life is prolonged, and the battery has a high circulation capacity retention rate.

An electrolyte, a battery cell, and a vehicle with a vehicle battery is provided. The electrolyte includes a ternary salt, dual-cyclic solvents, a linear carbonate solvent, and quaternary additives. The ternary salt includes lithium hexafluorophosphate (LiPF6), lithium bis(fluorosulfonyl)imide (LiFSI), and lithium difluoro(oxalate)borate (LiDFOB). The dual-cyclic solvents include ethylene carbonate (EC) between 0-30% by volume and fluoroethylene carbonate (FEC) between 0-30% by volume. The linear carbonate solvent includes at least one of ethyl methyl carbonate (EMC), dimethyl carbonate (DMC), or diethyl carbonate (DEC). The linear carbonate solvent is between 60-80% by volume. The quaternary additives include vinylene carbonate (VC) between 0.5-2% by weight, trimethylsilyl (TMSi) between 0.25-1% by weight, bis(2,2,2-trifluoroethyl) carbonate (DFDEC) between 0.5-2% by weight, and succinic anhydride (SA) between 0.25-1% by weight.

The invention relates to the technical field of batteries, in particular to an electrolyte without ethylene carbonate and a battery. The electrolyte comprises fluoroethylene carbonate, diethyl carbonate, propylene carbonate and a compound A, and the compound A is at least one of ethyl propionate and propyl propionate; based on the total mass of the electrolyte, the mass content w1 of the fluoroethylene carbonate is 10-30%; the mass content w5 of the diethyl carbonate is 5%-25%; the content w6 of the propylene carbonate is 5%-28%; the mass content of the compound A is w2, and w2 is 25%-60%; under the condition that the compound A is a combination of ethyl propionate and propyl propionate, the mass content of ethyl propionate is greater than that of propyl propionate; and 1.04 < = w1 / w5 < = 3.5. Comprising the electrolyte provided by the invention is improved in high-temperature stability, dynamic performance and cycle performance.

The present application relates to an electrochemical device comprising a positive electrode comprising a positive electrode current collector and a positive electrode active material layer on at least one surface of the positive electrode current collector, the positive electrode active material layer comprising a positive electrode active material, the positive electrode active material comprising a nickel-containing material, the weight percentage of the nickel-containing material is not less than 70%; the electrolyte comprises lithium bis (fluorosulfonyl) imide and lithium hexafluorophosphate, based on the total weight of the electrolyte, the weight percentage content of the lithium bis (fluorosulfonyl) imide is a%, the weight percentage content of the lithium hexafluorophosphate is b%, a + b is more than 12 and less than 20, a / b is more than 0.2 and less than 0.75, and the electrolyte further comprises a first compound, the first compound comprises at least one of methyl ethyl carbonate or diethyl carbonate, the weight percentage content of the first compound is c% based on the total weight of the electrolyte, and c is smaller than 10.

The utility model discloses a diethyl carbonate loading cooling and heat preservation device which comprises a bottom plate, a plurality of first cooling plates transversely arranged at the top end of the bottom plate, a plurality of second cooling plates longitudinally arranged at the top end of the bottom plate, a first water inlet pipe and a first water outlet pipe, the first water inlet pipe and the second water outlet pipe are connected with each second cooling plate, the first water outlet main pipe is connected with the first water outlet pipes jointly, the second water outlet main pipe is connected with the second water outlet pipes jointly, and the first water inlet main pipe is connected with the water inlet ends of the first water inlet pipes jointly. The first water inlet main pipe is connected with the water inlet ends of the first water inlet pipes, the second water inlet main pipe is connected with the water inlet ends of the second water inlet pipes, the first water tank is connected with the first water outlet main pipe and the second water outlet main pipe, the cooler is connected with the first water tank, and the first water inlet main pipe and the second water inlet main pipe are both connected with the second water tank. According to the utility model, the purpose of cooling and heat preservation when diethyl carbonate is loaded and transported can be achieved.

The invention provides a preparation method of diethyl malonate and a preparation method of valproic acid, and belongs to the technical field of organic synthesis. According to the method, diethyl carbonate and ethyl acetate are taken as initial raw materials, the ethyl acetate has three alpha-H and loses one alpha-H under the attack of strong base, so that ethyl acetate enol negative ions are formed, and ethyl acetate carbon negative ions are obtained through rearrangement; carrying out nucleophilic addition on carbonyl of diethyl carbonate by using the ethyl acetate carbon negative ions to obtain an addition intermediate, and then removing ethanol negative ions from the addition intermediate to obtain diethyl malonate; by controlling the reaction temperature, ethanol generated in the reaction process is continuously distilled out, so that the reaction is carried out in the forward direction, and side reactions are reduced to the greatest extent; as the condensation catalyst used in the invention has strong nucleophilicity and alkalinity, the use of the aprotic solvent can avoid the consumption of the condensation catalyst by the solvent.

The invention belongs to the technical field of lithium ion battery electrolytes, and particularly relates to a non-combustible electrolyte for a silicon negative electrode lithium ion battery and a preparation method of the non-combustible electrolyte, the non-combustible electrolyte comprises a lithium salt and a mixed solvent, the mixed solvent comprises ethyl 1, 1, 2, 3, 3, 3-hexafluoropropyl ether, diethyl carbonate and fluoroethylene carbonate, ethyl 1, 1, 2, 3, 3, 3-hexafluoropropyl ether, diethyl carbonate and fluoroethylene carbonate, and ethyl 1, 1, 2, 3, 3, 3-hexafluoropropyl ether, diethyl carbonate and fluoroethylene carbonate are added into the mixed solvent. The volume ratio of the 1, 1, 1, 3, 3-hexafluoropropyl ether to the diethyl carbonate to the fluoroethylene carbonate is (3-20): (2-5): (1-5). According to the invention, the cycle life and the safety performance of the silicon-based negative electrode battery are remarkably improved, and the method has important significance for promoting the development of high-energy-density batteries.

The invention discloses a sodium ion battery capable of improving rapid charging performance, performance breakthrough is realized through common optimization design of multiple components of positive and negative electrode materials, a diaphragm and electrolyte, and the positive electrode material is composed of sodium nickel iron manganese oxide, polyvinylidene fluoride, conductive carbon black and carbon nanotubes; a negative electrode material adopts a hard carbon material matched with a conductive agent and a composite binder, and the binder comprises sodium carboxymethyl cellulose, 3-(5-(2-nitrophenyl)-2-furan) acrylic acid and 4-(hydroxymethyl) phenylboronic acid pinacol ester; the diaphragm is a ceramic coating polyvinyl base membrane, the electrolyte takes sodium hexafluorophosphate as an electrolyte and is matched with an electrolyte additive and a composite solvent, and the electrolyte additive comprises three to five of sodium bis (fluorosulfonyl) imide, sodium difluorophosphate, sodium difluoro (oxalato) borate, ethylene sulfate, fluoroethylene carbonate and ethylene sulfite. The composite solvent comprises methyl ethyl carbonate, propylene carbonate and diethyl carbonate.

Electrolyte blends for lowering resistance and enhancing charge-discharge cycle life in lithium-ion batteries (LiB) containing silicon include a lithium additive in a solvent. The solvent may include diethyl carbonate (DEC) and / or lithium difluorooxalatoborate (LiDFOB).

The invention discloses an ultrahigh-temperature long-cycle sodium-ion battery electrolyte, which belongs to the technical field of sodium-ion batteries, and comprises a sodium salt, an additive and an organic solvent, the sodium salt comprises sodium hexafluorophosphate and sodium bis (fluorosulfonyl) imide, and the proportion of the sodium bis (fluorosulfonyl) imide is 0.6 to 0.8; the additives comprise fluoroethylene carbonate, vinylene sulfate, sodium difluorophosphate, sodium bis (oxalato) borate and methylene methanedisulfonate; the organic solvent comprises ethylene carbonate, propylene carbonate, diethyl carbonate and ethyl methyl carbonate. According to the sodium-ion battery electrolyte disclosed by the invention, the proportion of the composite sodium salt is precisely regulated and controlled, and the composite sodium salt and the additive form a synergistic effect to generate a high-temperature-resistant SEI film rich in inorganic components, so that the side reaction of the battery at a high temperature is reduced, and the high-temperature cycle life of the battery is greatly prolonged.

The invention relates to the technical field of organic synthesis, in particular to a method for co-producing methyl ethyl carbonate and diethyl carbonate through homogeneous catalysis, which comprises the following steps: by taking organic sulfonate of 0.5-10% bordering acid metal ions as a catalyst, reacting for 6-9 hours at 73-80 DEG C according to the molar ratio of dimethyl carbonate to ethanol being 1: (5-12); and carrying out atmospheric distillation on the reacted material, and collecting a fraction at 64-130 DEG C to obtain a mixed fraction containing the ethyl methyl carbonate and the diethyl carbonate. According to the technical scheme, the catalyst is superior to an existing catalyst in the aspects of catalytic activity, compatibility and stability, ester exchange can be efficiently catalyzed to co-produce ethyl methyl carbonate and diethyl carbonate, it is ensured that the yield of ethyl methyl carbonate is higher than that of diethyl carbonate, and a series of problems existing in the existing catalyst can be solved.

The application discloses a kind of composite solid-state polymer electrolyte and preparation method and application thereof.A kind of composite solid-state polymer electrolyte, preparation raw material includes trifluoromethanesulfonylimide lithium, polyvinylidene fluoride-hexafluoropropylene and modified cellulose derivative;Modified cellulose derivative is obtained by modification of organic modifier to cellulose derivative;Organic modifier includes at least one of N, N-dimethylformamide, dimethyl sulfoxide, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, 1,2-dimethoxyethane.The composite solid-state polymer electrolyte of the application has high ionic conductivity, wide electrochemical window, excellent cycle performance of solid-state polymer electrolyte, and the highest stable value of electrochemical window can reach 4.8V.The interaction between modified cellulose derivative and LiTFSI, PVDF-HFP is stronger under high salt system, and the obtained system has higher electrochemical stability.

This invention relates to a lithium secondary battery comprising a positive electrode, a negative electrode, a separator disposed between the positive and negative electrodes, and a non-aqueous electrolyte. The positive electrode comprises a positive electrode active material, which comprises a lithium transition metal oxide represented by the following chemical formula A. The non-aqueous electrolyte comprises a lithium salt, an organic solvent, and an additive. The organic solvent comprises a linear carbonate, which comprises diethyl carbonate, and the amount of diethyl carbonate present is from 5% to 25% by volume relative to the total volume of the organic solvent. The additive comprises lithium dioxalatoborate. [Chemical Formula A]Li 1+x [Ni a Co b Mn c M 1 d O 2+w In the above chemical formula A, 0 ≤ x ≤ 0.5, a + b + c + d = 1, 0.5 ≤ a ≤ 0.7, 0 ≤ b ≤ 0.15, c = 1 - a - b - d, 0 ≤ d ≤ 0.1, 0 ≤ b / a ≤ 0.2, 1 ≤ a / c ≤ 3, 0 ≤ w ≤ 1, and M 1 It is selected from at least one of W, Cu, Fe, V, Cr, Ti, Zr, Zn, Al, In, Ta, Y, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B and Mo.

The method comprises the following steps: preparing a standard solution, namely diluting an HDI (hexamethylene diisocyanate) standard substance by using a propylene carbonate-diethyl carbonate mixed solvent to obtain a standard solution mother solution, weighing the standard solution mother solution, diluting by using a mobile phase acetonitrile-methanol-water mixed solution, filtering, and drying to obtain the standard solution; adding a nitric acid aqueous solution to obtain a standard solution; preparing a to-be-detected sample solution: taking a to-be-detected lithium ion battery electrolyte sample, diluting the to-be-detected lithium ion battery electrolyte sample with the mobile phase according to the theoretical concentration value of HDI, and then adding the nitric acid aqueous solution to obtain the to-be-detected sample solution; instrument determination: using a liquid chromatograph with a differential refraction detector; performing chromatographic analysis on the standard solution and the to-be-detected sample solution, and recording peak areas; and calculating to obtain the mass percentage content of HDI in the electrolyte sample to be detected by adopting an external standard method and single standard correction. The method has the advantages of reliability, stability, simplicity and convenience in operation and high accuracy.

The invention relates to the technical field of lithium ion batteries, in particular to a method for detecting an SEI membrane of a lithium ion battery. The method is used for rapidly evaluating the film forming condition of the SEI film, and the specific process comprises the following steps: disassembling a lithium ion battery, taking out a negative electrode material in different charge states, and storing the negative electrode material and EMC (ethyl methyl carbonate) at 60-70 DEG C for 2-14 days; the content of EMC, DMC (dimethyl carbonate) and DEC (diethyl carbonate) after reaction is detected through a gas chromatography technology, and then the quality of the SEI film is evaluated; the battery with a good SEI film forming effect is less in EMC decomposition and more in residual amount, and the battery with a poor film forming effect is opposite to the battery with a poor film forming effect; therefore, by analyzing the residual amount of the EMC, the film forming quality of the SEI film of the battery can be quickly evaluated, and the cycle life and the performance of the battery can be indirectly predicted; compared with a traditional long-time cycle test method, the method has the remarkable time efficiency advantage.

The invention relates to a gel electrolyte precursor and a preparation method thereof, a gel electrolyte and a battery. The gel electrolyte precursor comprises a lithium salt, a solvent, an additive, a monomer and an initiator, wherein in terms of the total volume of the solvent, the solvent is prepared from the following components: 3v% to 15v% of ethylene carbonate, 5v% to 25v% of propylene carbonate, 7v% to 35v% of diethyl carbonate and 50v% to 85v% of methyl ethyl carbonate. According to the invention, four substances including ethylene carbonate, propylene carbonate, diethyl carbonate and ethyl methyl carbonate are compounded as a solvent, and when the solvent is used in a solid-state lithium ion battery with a high nickel / silicon negative electrode, efficient complexing and dissociation effects of lithium ions can be synergistically achieved, so that a stable positive and negative electrode electrolyte interface film is formed; and positive electrode gas production, electrode structure collapse, silicon negative electrode pulverization, lithium dendrite growth and the like are effectively inhibited, so that the problems of poor cycle performance and low coulombic efficiency of the high-energy-density solid-state lithium ion battery are solved.

The application relates to a wide-temperature-range semi-solid electrolyte, a lithium battery and a preparation method thereof, wherein the wide-temperature-range semi-solid electrolyte is composed of Li6PS5Cl as a solid component and a mixed solution of fluorinated carbonate, diethyl carbonate, LiPF6, LiFSI and vinyl sulfate as a solvent. The application selects a sulfide inorganic semi-solid electrolyte with high low-temperature conductivity and good high-temperature thermal stability, and combines a composite electrolyte solvent with high boiling point and low viscosity, so that the working performance of the lithium battery in high and low temperature environments is improved while the high energy density of the lithium battery is ensured.

The invention discloses a preparation method of methanesulfonic acid-2-propyn-1-ol, which comprises the following steps: adding propargyl alcohol, methylsulfonyl chloride and triethylamine into an organic solvent, reacting to generate a reaction solution containing a methanesulfonic acid-2-propyn-1-ol crude product, the organic solvent comprising diester carbonate and acetate; or propargyl alcohol, methylsulfonyl chloride and triethylamine are added into an organic solvent to react to generate a reaction solution containing a methanesulfonic acid-2-propargyl-1-alcohol crude product, and the organic solvent comprises any one or any combination of more than one of dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate or ethyl acetate; filtering and concentrating the reaction liquid to obtain a crude product of the methanesulfonic acid-2-propyn-1-ol; and carrying out molecular distillation on the methanesulfonic acid-2-propyn-1-ol crude product, so as to obtain the methanesulfonic acid-2-propyn-1-ol.

One embodiment of the present invention relates to a lithium secondary battery including a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte, wherein the positive electrode includes a positive electrode active material that includes a perlithiated manganese-rich oxide containing 50 mol % or more of Mn based on all metals excluding lithium and having a molar ratio of lithium to transition metals exceeding 1, and the non-aqueous electrolyte includes a lithium salt and an organic solvent, the organic solvent including a first organic solvent and a second organic solvent, the first organic solvent including ethylene carbonate, and the second organic solvent including diethyl carbonate and propyl propionate.

The invention is suitable for the technical field of materials, and provides a high-entropy electrolyte, a preparation method thereof and a high-voltage lithium ion battery. The high-entropy electrolyte comprises a lithium salt and a high-entropy solvent; the high-entropy solvent is composed of ethylene carbonate, dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate and dipropyl carbonate. According to the present invention, the ethylene carbonate, the dimethyl carbonate, the ethyl methyl carbonate, the diethyl carbonate and the dipropyl carbonate are combined to form the high-entropy solvent system, the solvation structure is adjusted through the super entropy, the high-voltage interface charging and discharging are adapted, the novel positive electrode is matched, the high capacity retention rate requirement is met, the cycle stability and the energy density of the battery are significantly improved, and the service life of the battery is significantly prolonged.

The present invention relates to a lithium secondary battery comprising a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte, wherein the positive electrode comprises a positive electrode active material, the positive electrode active material comprising a perlithiated manganese-rich oxide containing 50 mol % or more of Mn among all metals excluding lithium and having a molar ratio of lithium to transition metals exceeding 1, the non-aqueous electrolyte comprising a lithium salt, an organic solvent, and an additive, the organic solvents comprising a first organic solvent and a second organic solvent, the first organic solvent comprising ethylene carbonate and the second organic solvent comprising diethyl carbonate, and the additive comprising a cyclic sulfur oxide represented by a specific chemical formula.

The application relates to a preparation method of a lithium difluorodioxalate phosphate concentrated solution, the lithium difluorodioxalate phosphate concentrated solution is composed of lithium difluorodioxalate phosphate and an aprotic solvent, the aprotic solvent includes any one or a combination of at least two of diethyl carbonate, methyl ethyl carbonate, ethylene carbonate or propylene carbonate, and the concentration of lithium difluorodioxalate phosphate in the lithium difluorodioxalate phosphate concentrated solution is 10-35 wt%. The lithium difluorodioxalate phosphate concentrated solution provided by the application exists in the state of an aprotic electrolyte, an evaporation crystallization process is omitted, and the production cost is reduced; the product can be transported through a pipeline, and the product transportation cost is reduced; compared with lithium difluorodioxalate phosphate solid, the process of re-dissolving during use is omitted, the risk of impurity introduction is avoided, and the use cost is reduced.