183 results about "Vinylene carbonate" patented technology

The invention provides a non-aqueous electrolyte, a lithium ion battery, a battery module, a battery pack and a power utilization device, the non-aqueous electrolyte comprises a lithium salt, an organic solvent and an electrolyte additive, and the electrolyte additive comprises 1, 3-propane sultone, fluoroethylene carbonate, vinylene carbonate, lithium tetrafluoroborate and a compound I shown in the formula I. The non-aqueous electrolyte is applied to the lithium ion battery, and the cycle life of the lithium ion battery is prolonged.

Secondary battery, including a positive electrode sheet comprising a positive electrode current collector and a positive electrode film layer, wherein the positive electrode film layer is arranged on at least one side of the positive electrode current collector and the positive electrode film layer comprises a positive electrode active material; a negative electrode sheet, wherein the negative electrode sheet comprises a negative electrode current collector and a negative electrode film layer, wherein the negative electrode film layer is arranged on at least one side of the negative electrode current collector and the negative electrode film layer comprises a negative electrode active material, wherein the negative electrode active material comprises graphite and the powder compaction density of the negative electrode active material at 20,000 N is 1.5 g / cm³ 3 up to 1.85 g / cm³ 3 is; and an electrolyte comprising an organic solvent and an organic additive, wherein the organic solvent comprises a first solvent, the first solvent comprising cyclic carbonate, and the mass fraction of the first solvent, based on the total mass of the electrolyte, is 17% to 34%; wherein the organic additive comprises a first and a second additive, the first additive comprising vinylene carbonate and the second additive comprising an ethylene carbonate derivative, and the mass fraction of the first additive is 1.5% to 8% and the mass fraction of the second additive is 0.5% to 4%, each based on the total mass of the electrolyte.

Systems and methods are provided for using electrolytic compositions in lithium ion batteries. In one example, an electrolytic composition may include vinylene carbonate, fluoroethylene carbonate, 1,3-propane sultone, ethylene sulfite, and a conducting salt including no less than 80 mol % of lithium bis(fluorosulfonyl)imide. In this way, a capacity retention of the lithium ion battery may be maintained, such as during high-temperature storage at 100% state of charge.

Lithium secondary battery, comprehensive a positive electrode, a negative electrode, a separator and a non-aqueous electrolyte, wherein: the positive electrode comprises a positive electrode active material, wherein the positive electrode active material comprises lithium iron phosphate particles and the positive electrode has a loading amount of 450 mg / 25 cm² 2 up to 740 mg / 25 cm 2 exhibits; and the non-aqueous electrolyte comprises a lithium salt, an organic solvent and an additive, wherein the organic solvent comprises a solvent based on a cyclic carbonate and a solvent based on a linear carbonate, wherein the solvent based on a cyclic carbonate comprises ethylene carbonate and the solvent based on a linear carbonate comprises dimethyl carbonate, the additive comprises vinylene carbonate and the dimethyl carbonate is present in an amount of 5 vol% to 75 vol% in the organic solvent and the weight ratio of vinylene carbonate to dimethyl carbonate is greater than 0 to 0.2 or less.

The invention discloses an acetonitrile electrolyte and a sodium ion battery thereof, and aims to provide an electrolyte which not only can keep the advantage of high conductivity of acetonitrile and widen the electrochemical window of the electrolyte, but also can be well compatible with a positive electrode and a negative electrode to form a stable interface. The invention also provides a sodium ion battery capable of improving the rate capability of the acetonitrile electrolyte and realizing ultrafast charge. The acetonitrile electrolyte comprises a solvent acetonitrile, wherein a composite film-forming agent, NaPF6 and NaClO4 are added into the acetonitrile; the mass ratio of the acetonitrile to the composite film forming agent to the NaPF6 to the NaClO4 is 100: (2 to 5): (17.1 to 20.3): (0.78 to 3.11); the composite film-forming agent is composed of vinylene carbonate and ethylene sulfate; belongs to the technical field of sodium-ion batteries.

An electrolyte for a battery cell, a battery cell for a vehicle and a method of forming a battery cell. The electrolyte includes a combination of lithium ion salts including lithium hexafluorophosphate (LiPF6), lithium bis(fluorosulfonyl)imide, and lithium difluoro(oxalato)borate. The electrolyte also includes a carbonate solvent including fluoroethylene carbonate, ethyl methyl carbonate, and a carboxylic acid ester exhibiting the following formula:wherein R1 and R2 are individually an unsubstituted alkyl group including in the range of 1 carbon to 2 carbons, wherein the combination of lithium ion salts is dispersed in the carbonate solvent. The electrolyte further includes vinylene carbonate. The electrolyte does not include ethyl carbonate.

A lithium-ion battery electrolyte includes LiPF6 and an organic compound composition. The organic compound composition includes (1) vinylene carbonate (VC), (2) fluoroethylene carbonate (FEC), and (3) at least one ester (ES). A mole fraction of the LiPF6 in the electrolyte is approximately c(LiPF6) mol. %. A mole fraction of the VC in the electrolyte is approximately c(VC) mol. %. A mole fraction of the FEC in the electrolyte is approximately c(FEC) mol. %. A mole fraction of the ES in the electrolyte is approximately c(ES) mol. %. In some embodiments, the mole fractions c(LiPF6), c(VC), c(FEC), and c(ES) satisfy the following relations:8≤c(LiPF6)≤16;0.5≤c(VC)≤5;10≤c(FEC)≤26; and40≤c(ES)≤75.

The invention discloses a positive pole piece and a preparation method thereof, a diaphragm-free battery and a battery. The positive pole piece comprises a positive pole current collector and a positive pole active material layer arranged on at least one side of the positive pole current collector, the positive pole active material layer comprises a polymer, and the polymer is formed by polymerizing at least one of small molecules of the following raw material components: vinylethylene carbonate, vinylene carbonate, 2, 3, 4-trimethyl-1, 3-pentanedione, 2, 3, 4-trimethyl-1, 3-pentanedione and 2, 3, 4-trimethyl-1, 3-pentanedione. The adhesive is prepared from 2, 4-hexadienoic acid, allyl trifluoroacetate, diethyl allylmalonate, allyl methacrylate, allyl chloroformate, allyl phenylacetate, allyl acetate, allyl 4-hydroxybenzoate and allyl phenoxyacetate. The adhesive is prepared from the following raw materials: 1, 4-hexadienoic acid, allyl trifluoroacetate, diethyl allylmalonate, allyl methacrylate, allyl chloroformate, allyl phenylacetate, allyl acetate, allyl 4-hydroxybenzoate and allyl phenoxyacetate. The positive pole piece provided by the invention comprises the polymer, so that the interface impedance can be reduced, and the rate capability of the battery can be improved.

The invention discloses a new lithium battery material and a preparation method thereof, and relates to the technical field of lithium ion batteries, the new lithium battery material comprises an electrolyte, and the electrolyte comprises a solvent, a composite lithium salt and a functional additive; the solvent comprises fluoro-carbonate, ionic liquid and fluoro-ether; the composite lithium salt comprises lithium bis (fluorosulfonyl) imide (LiFSI), lithium bis (trifluoromethyl) sulfonyl imide (LiTFSI) and lithium bis (oxalato) borate (LiBOB); the functional additive comprises silane modified vinylene carbonate and tris (trimethylsilyl) phosphate. The composite lithium salt is matched with the functional additive and the solvent, so that the battery has relatively good discharge performance and cycle performance in a temperature range of-30 DEG C to 70 DEG C, and has good wide-temperature applicability.

The embodiment of the application discloses a battery monomer, a battery device and a power utilization equipment. The battery monomer comprises: a shell, the shell comprising a shell body, a positive electrode end cover assembly and a negative electrode end cover assembly; an electrode assembly, the electrode assembly comprising a positive electrode sheet and a negative electrode sheet, and the electrode assembly is a laminated structure; the electrode assembly comprises a main body part and a tab part located at an end face of the main body part, and a size of the main body part in a first direction is greater than 400 mm; a single surface area density of a positive electrode film layer of the positive electrode sheet is greater than 375 mg / 1540.25 mm 2 ; an electrolyte, the electrolyte comprising a lithium salt and an additive; the lithium salt comprising at least one of lithium hexafluorophosphate and lithium bisfluorosulfonylimide; the additive comprising at least one of vinylene carbonate and a silane additive; and a mass content of the lithium salt is 14% to 20% and a mass content of the additive is 2% to 5% based on a total mass of the electrolyte. The battery monomer provided by the application considers both high energy density and fast charging long service life.

The invention relates to the technical field of electrochemistry, in particular to an electrolyte and a secondary battery. The electrolyte comprises an organic solvent, an electrolyte and additives, the additives comprise a first additive, a second additive and a film-forming additive, the first additive is selected from at least one of compounds shown in the formula I, the second additive is selected from at least one of compounds shown in the formula II, and the film-forming additive is selected from at least one of compounds shown in the formula II. The film-forming additive is selected from at least one of vinylene carbonate, vinylethylene carbonate, fluoroethylene carbonate, ethylene sulfate, 1, 3-propane sultone, lithium difluorophosphate and lithium bis (oxalato) borate, and the first additive, the second additive and the film-forming additive have a synergistic effect, so that a composite film with a stable structure can be formed on the surface of an electrode; and the transmission of lithium ions on an electrode / electrolyte interface is facilitated, so that the high-temperature performance of the secondary battery and the cycle performance of the secondary battery under high voltage are improved.

The application discloses a non-aqueous electrolyte and a lithium ion battery thereof. The non-aqueous electrolyte comprises a lithium salt, a non-aqueous organic solvent and an additive, the additive comprises a first additive, a second additive and a third additive, the first additive is a compound I shown in a structural formula I, the second additive is vinylene carbonate, and the third additive is 1,3-propane sulfone lactone, wherein R1-R3 are each independently selected from hydrogen, halogen, a linear alkyl group or a cyclic alkyl group. The non-aqueous electrolyte of the application can effectively inhibit the dissolution of manganese ions and improve the high-temperature storage and high-temperature cycle performance of a lithium ion battery of a manganese iron lithium phosphate by the synergistic cooperation of the compound I with a uracil structure, vinylene carbonate and 1,3-propane sulfone lactone as the additive.

The invention relates to the technical field of lithium ion batteries and solid-state batteries, and discloses a lithium metal battery based on in-situ polymerization ultrathin solid-state electrolyte interface modification, which is characterized in that monomer vinylene carbonate, a plasticizer, a metal lithium salt and an initiator azodiisobutyronitrile are subjected to heating in-situ polymerization to form an ultrathin solid-state electrolyte; meanwhile, the negative electrode side of the diaphragm is coated with the Ag2Se interface layer, in the standing process of the battery, Ag2Se reacts with lithium metal to generate LiAg alloy, the LiAg alloy has extremely high lithium ion conductivity, and the interface impedance can be greatly reduced, so that the negative electrode interface is effectively modified, the lithium ion flow is homogenized, the growth of lithium dendrites is inhibited, the cycling stability and safety of the battery are improved, and the service life of the battery is prolonged. The thickness of the prepared solid electrolyte can be controlled below 20 microns, and finally, the interface impedance is greatly reduced, so that the solid electrolyte is suitable for the field of high-energy-density lithium metal batteries.

A battery. The battery comprises a positive electrode sheet and an electrolyte; the positive electrode sheet comprises lithium iron phosphate; the electrolyte comprises vinylene carbonate and a silicon-based fluorophosphate compound represented by formula I: formula I; in formula I, R1, R2 and R3 are each independently selected from any one of H, F, C1-C4 alkyl, C1-C4 fluoroalkyl, C2-C4 alkenyl, C2-C4 fluoroalkenyl, C2-C4 alkynyl, C2-C4 fluoroalkynyl, C5-C7 cycloalkyl, R4 substituted phenyl, and R5 substituted benzyl, and R4 and R5 are each independently selected from any one of C1-C4 alkyl, C2-C4 alkenyl, C2-C4 alkynyl, C1-C4 fluoroalkyl, C2-C4 fluoroalkenyl, C2-C4 fluoroalkynyl, and F.

The invention relates to the technical field of lithium ion battery electrolyte, and particularly discloses lithium ion battery low-temperature electrolyte and a preparation method thereof. According to the invention, the low-viscosity halogenated propionate carboxylic ester and the perfluoroalkyl methyl ether solvent are cooperated, so that the freezing point and the system viscosity are greatly reduced, and good ion transmission capability at-60 DEG C is ensured; lithium salts such as fluorinated aryl sulfonimide lithium are selected and matched with functional additives such as vinylene carbonate, fluoroethylene carbonate and ethylene sulfite to synergistically construct a stable solid electrolyte interfacial film with high ionic conductivity, so that side reaction and capacity fading at low temperature are remarkably inhibited; meanwhile, the siloxane conductive agent and the long-chain glycol dimethyl ether are introduced, so that the permeability, the ion migration rate and the low-temperature stability of the electrolyte are further improved. The electrolyte provided by the invention can be stably applied to new energy automobiles and high-altitude outdoor energy storage systems in severe cold areas of-60 DEG C, and the application range of the lithium ion battery is greatly expanded.

The application provides a method for preparing vinylene carbonate without solvent. The method comprises the following steps: mixing chlorovinyl carbonate with a catalyst, heating to a reaction temperature, introducing a protective gas, and carrying out a dechlorination reaction; after the reaction is completed, filtering the reaction solution, and subjecting the filtrate to rectification, crystallization and melting to obtain vinylene carbonate; the catalyst is a supported Schiff base metal complex catalyst, which comprises an A12O3 carrier and an active component supported on the carrier, and the active component is one or more of Cu(II) Schiff base complex, Mn(II) Schiff base complex and Co(II) Schiff base complex. The method has the characteristics of high selectivity, high product conversion rate, low energy consumption and low discharge amount of three wastes; the reaction condition is mild, and the method has the characteristics of high activity, high selectivity, few side reactions, high yield, simple post-treatment, recyclable catalyst and green production process.

The invention relates to the technical field of lithium ion batteries, and discloses an electrolyte and a lithium ion battery. The electrolyte comprises a carbonic ester solvent and a carboxylic ester solvent, and the mass ratio of the carbonic ester solvent to the carboxylic ester solvent is (7: 3)-(9: 1); the composite additive comprises a first functional additive and a second functional additive, the mass of the composite additive accounts for 2%-8% of the total mass of the electrolyte, the mass ratio of the first functional additive to the second functional additive is (1: 10)-(10: 1), the first functional additive comprises vinylene carbonate, fluoroethylene carbonate, 1, 2, 4-trimethyl-1, 3-pentanediol monoisobutyrate, and the second functional additive comprises vinylene carbonate, fluoroethylene carbonate, 1, 2, 4-trimethyl-1, 3-pentanediol monoisobutyrate and 1, 2, 4-trimethyl-1, 3-pentanediol monoisobutyrate. The first functional additive comprises any one of 1, 3-propane sultone, and the second functional additive comprises at least one of ethylene sulfate and lithium difluorophosphate. The electrolyte provided by the invention is helpful for improving the fast charging performance of the lithium ion battery and the electrical performance at a low temperature.

The invention provides a method for regulating and controlling the liquid injection amount of a lithium ion battery and application of the method, and relates to the technical field of batteries. The method for regulating and controlling the liquid injection amount of the lithium ion battery provided by the invention comprises the following steps: carrying out a charge-discharge cycle test on the lithium ion battery to obtain the content of vinylene carbonate in a battery electrolyte under different cycle numbers; adding a target life point (x target, 0) based on the target life x target of the lithium ion battery; fitting the target life point and the measured data to obtain a fitting curve of the number of cycles and the content of vinylene carbonate; and calculating the content y'of vinylene carbonate when the number of cycles is 0 according to the fitted curve, and comparing the y 'with the content y0 of vinylene carbonate in the electrolyte of the lithium ion battery before the charge-discharge cycle test. According to the method, the minimum liquid injection amount required for reaching the target service life can be scientifically determined, the waste of the electrolyte is avoided, and the production processability and the safety of the battery are improved.

A battery cell, a battery device, and an electric device. The battery cell comprises an electrode assembly and an electrolyte, wherein the electrode assembly comprises a positive electrode sheet and a negative electrode sheet; the positive electrode sheet comprises a lithium-containing phosphate; the negative electrode sheet comprises graphite particles; the electrolyte comprises a carboxylate ester solvent, a linear carbonate solvent, and an additive; the mass content of the carboxylate ester solvent is 10% to 30%; the mass content of the linear carbonate solvent is 10% to 50%; the mass content of the additive is 3% to 9%; the additive comprises 1,3-propane sultone having a mass content greater than or equal to 0, an ethylene carbonate derivative having a mass content greater than or equal to 0, and vinylene carbonate having a mass content greater than 0; and the ethylene carbonate derivative comprises a compound represented by formula A, wherein in formula A, Q1, Q2, Q3, and Q4 each independently comprise any one of a hydrogen atom, a halogen atom, a C1 to C5 alkyl group, or a C1 to C5 haloalkyl group, and Q1, Q2, Q3, and Q4 are not simultaneously hydrogen atoms.

Lithium-ion battery, characterized in that the filling coefficient a of the lithium-ion battery satisfies the following condition: 2.2 g / Ah ≤ a ≤ 2.8 g / Ah; the lithium-ion battery comprises an electrolyte, wherein the electrolyte contains a first solvent and an additive; The viscosity η of the first solvent meets the condition: η ≤ 0.6 mPa / s; The additive contains at least one of the following substances: vinylene carbonate, fluoroethylene carbonate, vinylethylene carbonate, ethylene sulfate and 1,3-propanesultone, and the mass fraction m of the additive in the electrolyte meets the condition: 5% ≤ m ≤ 12%.

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 field of battery electrolytes, in particular to an additive, an electrolyte containing the additive and a battery containing the electrolyte, the additive is trimethylsiloxy nitrile, and the electrolyte comprises an organic solvent, an electrolyte lithium salt and an additive, the additive in the electrolyte comprises one or more of trimethylsiloxy nitrile, fluoroethylene carbonate, ethylene sulfate, vinylene carbonate and 1, 3-propane sultone; the electrolyte lithium salt is a mixed lithium salt of lithium hexafluorophosphate and lithium difluorophosphate; the organic solvent comprises one or more of carbonic ester, carboxylic ester, fluoro-carbonic ester and fluoro-carboxylic ester. According to the additive, the electrolyte containing the additive and the battery containing the electrolyte, the cycle performance and the high-temperature performance of the ternary high-nickel lithium ion battery can be improved.

This invention discloses a method for synthesizing vinylene carbonate. The method includes: reacting chlorovinyl carbonate with triethylamine in the presence of compounds such as oxanthracene or thioxanthracene to generate a vinylene carbonate reaction solution; and then subjecting the reaction solution to vacuum filtration, distillation, and crystallization to obtain electronically pure vinylene carbonate (purity can reach 99.995% or higher). This method can effectively inhibit the polymerization of vinylene carbonate, avoid the formation of vinylene carbonate polymers, improve the yield of the elimination reaction and the overall heat transfer efficiency of the distillation process, reduce the difficulty of separation and purification, and reduce energy consumption, making it suitable for industrial production.

The invention belongs to the field of lithium batteries, and particularly relates to a sulfonic acid-based deep eutectic gel electrolyte and a preparation method and application thereof, the electrolyte comprises a eutectic electrolyte and a polymer monomer; the eutectic electrolyte comprises a hydrogen bond donor and a hydrogen bond acceptor, the hydrogen bond donor is a sulfonic acid substance, and the hydrogen bond acceptor is a lithium salt; the molar ratio of the sulfonic acid substance to the lithium salt is (4-2): 1; the eutectic electrolyte further comprises an additive, and the additive is one or more of vinylene carbonate, fluoroethylene carbonate and lithium nitrate; the polymer monomer is a cyclic ether substance; the polymer monomer further comprises a cross-linking agent, DOL polymerization is initiated by using lithium salt anions as an initiator through an in-situ polymerization process, an initiator with high reaction activity does not need to be additionally added, the preparation operation steps are greatly simplified, and meanwhile, the production link and the material cost are further reduced through the design of the in-situ polymerization sulfonic acid group deep eutectic electrolyte. And the preparation targets of low cost and easy large-scale preparation are achieved.

A multi-component synergistic siloxane electrolyte system and SEI film in-situ construction method belong to the technical field of electrochemical energy. The specific scheme is that the multi-component synergistic siloxane electrolyte system comprises a main solvent, a coordination diluent and a film-forming additive, the main solvent is a siloxane solvent, the coordination diluent is an ether solvent, and the film-forming additive is vinylene carbonate and fluoroethylene carbonate. The SEI in-situ construction method based on the multi-component synergistic siloxane electrolyte system comprises the following steps: step one, low-temperature discharge activation; step two, step-by-step temperature rising activation. Through the two-step activation process, the application creatively combines the 'densification' advantage of low-temperature film formation and the'mechanical stability' advantage of high-temperature film formation, so as to construct a high-quality SEI film with both excellent characteristics on the surface of TNO / WNO negative electrode in-situ.

A secondary battery and an electric device. A negative electrode sheet in the secondary battery comprises a negative electrode current collector and a negative electrode film layer, wherein the negative electrode film layer is arranged on at least one side of the negative electrode current collector, and the negative electrode film layer comprises a negative electrode active material. The negative electrode active material comprises a first graphite with a Dv50 particle size of 2.2-7.7 μm. The electrolyte comprises an organic solvent and an organic additive. The organic solvent comprises a first solvent which comprises a cyclic carbonate, and the mass content of the first solvent is 25-40% based on the total mass of the organic solvent. The organic additive comprises a first additive and a second additive, wherein the first additive comprises vinylene carbonate, and the second additive comprises an ethylene carbonate derivative, and the mass percentage of the first additive in the electrolyte is 2-10% and the mass percentage of the second additive in the electrolyte is 0.3-6% based on the total mass of the electrolyte.

In order to overcome the problems in existing lithium ion batteries having high compactness and high-specific-surface-area negative electrodes of serious side reactions of electrolytes and high gas production, the present invention provides a lithium ion battery, comprising a positive electrode, a negative electrode, and a non-aqueous electrolyte. The negative electrode comprises a negative electrode material layer, the compaction density of the negative electrode material layer is greater than or equal to 1.4 g / cm3, and the negative electrode material layer comprises a negative electrode active material, and the non-aqueous electrolyte comprises a solvent, an electrolyte salt, a vinylene carbonate, a fluoroethylene carbonate, and an unsaturated phosphate represented by structural formula 1, and the electrolyte salt comprises LiPF6 and LiFSI. The lithium ion battery provided by the present invention has good cycle performance, high and low temperature storage performance, and lithium precipitation resistance.

The invention belongs to the technical field of semi-solid batteries, and particularly relates to a semi-solid electrolyte, a preparation method of the semi-solid electrolyte, a semi-solid battery and application of the semi-solid battery, a non-aqueous electrolyte contained in the semi-solid electrolyte comprises electrolyte salt, an additive and an organic solvent, the additive comprises vinylene carbonate, and the organic solvent comprises ethyl methyl carbonate; the mass ratio of the vinylene carbonate to the methyl ethyl carbonate to the azo initiator is 1: (50-85): (0.01-0.15); the mass content of fluoroethylene carbonate in the semi-solid electrolyte precursor solution is less than 10 ppm, and the mass content of boron is less than 10 ppm. According to the invention, the fluoroethylene carbonate and boron element content, and the precise appropriate proportion and synergistic effect of the vinylene carbonate, the methyl ethyl carbonate, the azo initiator and other components are beneficial to obtaining the semi-solid battery with excellent high temperature resistance and excellent cycle performance at normal temperature and high temperature; the cycle life of the semi-solid battery is obviously prolonged, and the cycle stability is good.

This invention relates to the field of battery technology, and more particularly to a non-aqueous electrolyte, a lithium-ion battery, a battery module, a battery pack, and an electrical device. The non-aqueous electrolyte comprises a lithium salt, a non-aqueous organic solvent, and functional additives. The functional additives include compounds with the structure shown in Formula I and other additives; R1 and R2 are each independently selected from carbonyl, amide, and dimethylacetamide groups; R3, R4, R5, and R6 are each independently selected from hydrogen and fluorine; n is selected from 1 to 3; other additives are selected from one or more combinations of lithium difluorosulfonylimide, lithium trifluoromethanesulfonate, lithium fluorosulfonate, 2-propynyl methanesulfonate, methanedisulfonate methylene, fluoroethylene carbonate, spiroethylene sulfate, vinylene carbonate, and 1,3-propanesulfonate lactone. This invention, through the synergistic effect of compounds with the structure shown in Formula I and other additives, improves the low-temperature performance, rate performance, and cycle performance of lithium batteries.

The invention discloses an electrolyte for improving low temperature and cycle performance of a lithium iron phosphate battery and a high-capacity high-safety lithium iron phosphate battery, which comprises an organic solvent, a lithium salt and an additive, and is characterized in that the lithium salt is lithium hexafluorophosphate and / or lithium bis (fluorosulfonyl) imide; the organic solvent is one or more of cyclic carbonate and linear carbonate, and the additive comprises vinylene carbonate and a compound represented by a formula (1); in the formula (1), R is one or more of sulfonamide and derivatives thereof. The electrolyte provided by the invention shows good low temperature and cycle performance in the lithium ion battery, and enhances the competitiveness of the product on the premise of ensuring the safety.