161 results about "Difluorophosphate" patented technology

An object is to provide a nonaqueous electrolyte and a nonaqueous-electrolyte secondary battery which have excellent discharge load characteristics and are excellent in high-temperature storability, cycle characteristics, high capacity, continuous-charge characteristics, storability, gas evolution inhibition during continuous charge, high-current-density charge / discharge characteristics, discharge load characteristics, etc. The object has been accomplished with a nonaqueous electrolyte which comprises: a monofluorophosphate and / or a difluorophosphate; and further a compound having a specific chemical structure or specific properties.

A subject is to provide a nonaqueous electrolyte excellent in cycle performances such as capacity retention after cycling, output after cycling, discharge capacity after cycling, and cycle discharge capacity ratio, output characteristics, high-temperature storability, low-temperature discharge characteristics, heavy-current discharge characteristics, high-temperature storability, safety, high capacity, high output, high-current-density cycle performances, compatibility of these performances, etc. Another subject is to provide a nonaqueous-electrolyte secondary battery employing the nonaqueous electrolyte. The subjects have been accomplished with a nonaqueous electrolyte which contains a monofluorophosphate and / or a difluorophosphate and further contains a compound having a specific chemical structure or specific properties.

The present invention provides a simple method for producing a difluorophosphate from a source material, the difluorophosphate being useful as additives for nonaqueous electrolyte solutions for secondary batteries. In the method, a source material containing a carbonate and / or a borate is allowed to react with a source gas which contains P and F and which may further contain O as required. The source material may contain lithium carbonate. The source gas may be produced by decomposing LiPF6. The source gas may be produced in such a manner that LiPF6 and lithium carbonate are mixed and then subjected to reaction. The nonaqueous electrolyte solution contains the product obtained from the reaction.

The object of the present invention is to provide a nonaqueous electrolyte secondary battery which has excellent balance of general performance with respect to performance including durability, capacity, resistance, and output characteristics. Provided is a nonaqueous electrolyte battery comprising a positive electrode and a negative electrode each being capable of occluding and releasing metal ions, and a nonaqueous electrolyte solution, wherein the nonaqueous electrolyte solution contains an electrolyte, a nonaqueous solvent, and at least one compound selected from the group consisting of a compound having a fluorosulfonyl structure (—SO2F), a difluorophosphate, and an isocyanate compound, and wherein the negative electrode has a negative electrode active material containing metal particles capable of alloying with Li and graphite particles.

The invention discloses a high-capacity lithium-ion battery electrolyte of considering high-and-low temperature performance. The electrolyte comprises a non-aqueous solvent, lithium hexafluorophate, a negative film-forming additive, an inflatable inhibition additive and a low-impedance additive, wherein the negative film-forming additive is prepared from fluoroethylene carbonate which accounts for 3%-15% of total mass of the electrolyte; the inflatable inhibition additive is prepared from one or two of 1,3-propene sultone or anhydride compounds which account for 0.3%-5% of total mass of the electrolyte; and the low-impedance additive is prepared from one or two of lithium difluorophosphate and difluoride phosphate lithium oxalate which account for 0.2%-3% of total mass of the electrolyte. The electrolyte is suitable for a high-nickel positive electrode and silicon-carbon composite negative electrode lithium-ion battery; the high-temperature storage performance and the low-temperature discharge performance of the lithium-ion battery are improved while the room-temperature cycle performance is considered; and meanwhile, the invention further provides a preparation method of the electrolyte and the high-capacity lithium-ion battery of using the electrolyte.

This invention provides a nonaqueous electrolyte which is excellent in discharge load properties, as well as in high-temperature storage stability, cycling characteristics, high capacitance, continuous charge properties, storage stability, gas evolution suppression in continuous charging, charge / discharge properties at a high current density, discharge load properties and the like, and a rechargeable battery with a nonaqueous electrolyte. The nonaqueous electrolyte contains a monofluorophosphate and / or a difluorophosphate and further contains a compound having a specific chemical structure orspecific properties.

A difluorophosphate effective as an additive for a nonaqueous electrolyte for secondary battery is produced by a simple method from inexpensive common materials.The difluorophosphate is produced by reacting lithium hexafluorophosphate with a carbonate in a nonaqueous solvent. The liquid reaction mixture resulting from this reaction is supplied for providing the difluorophosphate in a nonaqueous electrolyte comprising a nonaqueous solvent which contains at least a hexafluorophosphate as an electrolyte lithium salt and further contains a difluorophosphate. Also provided is a nonaqueous-electrolyte secondary battery employing this nonaqueous electrolyte.

The invention discloses a high-nickel ternary lithium ion power battery electrolyte and a high-nickel ternary lithium ion power battery. The electrolyte includes a non-aqueous organic solvent, a lithium salt, a conductive additive, a film forming additive and an infiltration additive, wherein the conductive additive is lithium difluorophosphate, the film forming additive is ethylene sulfate, and the infiltration additive is at least one of fluorophosphazene and fluoroethylene carbonate; and synergism and mutual promotion of the three additives makes an excellent SEI film be formed on the surface of an electrode and effectively promotes all dynamic processes in the lithium ion battery. The power battery electrolyte has the advantages of good lithium ion transmission characteristic, good oxidation resistance, guaranteeing of high power characteristic and good cycle performances of the power battery, and high safety.

A nonaqueous electrolytic solution that can provide a battery that is low in gas generation, has a large capacity, and is excellent in storage characteristics and cycle characteristics contains an electrolyte and a nonaqueous solvent dissolving the electrolyte and further contains 0.001 vol % or more and less than 1 vol % of a compound represented by Formula (1) in the nonaqueous solvent. Alternatively, the nonaqueous electrolytic solution contains 0.001 vol % or more and less than 5 vol % of a compound represented by Formula (1) in the nonaqueous solvent and further contains at least one compound selected from the group consisting of cyclic carbonate compounds having carbon-carbon unsaturated bonds, cyclic carbonate compounds having fluorine atoms, monofluorophosphates, and difluorophosphates.In Formula (1), R1 to R3 each independently represent an alkyl group of 1 to 12 carbon atoms, which may be substituted by a halogen atom; and n represents an integer of 0 to 6.

A subject is to provide a nonaqueous electrolyte excellent in cycle performances such as capacity retention after cycling, output after cycling, discharge capacity after cycling, and cycle discharge capacity ratio, output characteristics, high-temperature storability, low-temperature discharge characteristics, heavy-current discharge characteristics, high-temperature storability, safety, high capacity, high output, high-current-density cycle performances, compatibility of these performances, etc. Another subject is to provide a nonaqueous-electrolyte secondary battery employing the nonaqueouselectrolyte. The subjects have been accomplished with a nonaqueous electrolyte which contains a monofluorophosphate and / or a difluorophosphate and further contains a compound having a specific chemical structure or specific properties.

Provided is an electrolyte solution additive including lithium difluorophosphate (LiDFP), a vinylene carbonate-based compound, and a sultone-based compound. Also, a non-aqueous electrolyte solution including the electrolyte solution additive and a lithium secondary battery including the non-aqueous electrolyte solution are provided. The lithium secondary battery including the electrolyte solution additive of the present invention may improve low-temperature output characteristics, high-temperature cycle characteristics, output characteristics after high-temperature storage, and swelling characteristics.

Provided is a non-aqueous electrolyte for a lithium secondary battery, which is prepared by adding predetermined additives to a non-aqueous electrolyte. The non-aqueous electrolyte includes: (a) lithium difluorophosphate, (b) an (oxalato)borate compound including one or more selected from lithium bis(oxalato)borate and lithium difluoro(oxalato)borate; and (c) fluoroethylene carbonate or a sultone based compound. The present invention provides a non-aqueous lithium secondary battery capable of having excellent low-temperature discharge efficiency and high-temperature storage efficiency while significantly decreasing a thickness increase rate of the battery at the time of being exposed to a high temperature for a long period of time.

The invention relates to a lithium ion battery electrolyte and a lithium ion battery, and belongs to the technical field of lithium ion batteries. The lithium ion battery electrode comprises an organic solvent, an electrolyte lithium salt, a low-impedance additive and a functional additive, wherein the low-impedance additive comprises lithium difluorophosphate and lithium difluoro bis(oxalato) phosphate, the functional additive is an arbitrary one or a combination of tris(trimethylsilyl) borate and tris(trimethylsilyl) phosphate, and the functional additive accounts for 0.1-4% of the total mass of the lithium ion battery electrolyte. The lithium ion battery electrolyte can participate in negative electrode film formation, the interface impedance of the electrolyte is reduced, and the low-temperature performance of the electrolyte is improved; and a flexible and high-temperature stable electrode interface film also can be formed on a surface of a high-capacity silicon carbon composite negative electrode material, the breakage of an SEI film caused by silicon expansion during the circulation process is timely repaired, and the cycle property of the silicon carbon negative electrode lithium ion battery is improved.

The invention discloses a security lithium-ion power battery electrolyte and a lithium-ion power battery. The electrolyte comprises a non-aqueous organic solvent, a lithium salt, a low-impedance film-forming additive and an overcharge protection additive, wherein the low-impedance film-forming additive is at least one of lithium difluorophosphate and ethylene sulfate; and the overcharge protection additive is an aromatic or fluorinated aromatic compound containing a benzene ring. When the lithium-ion power battery is overcharged, the overcharge protection additive disclosed by the invention can be subjected to oxidation polymerization on the surface of an electrode or can be decomposed to produce a gas, so that the internal resistance of the battery is instantly increased, continuous charging for the battery is blocked and combustion and explosion of the battery are effectively avoided. Meanwhile, the low-impedance film-forming additive can form a stable SEI film on the surface of the electrode, side reaction of the overcharge protection additive and the electrode is inhibited and the internal resistance of the battery is reduced, so that the long cycle performance and the output characteristic of the power battery are improved.

The invention belongs to the technical field of chemical synthesis and in particular to a preparation method of lithium difluorophosphate. In the method, lithium difluorophosphate is obtained by reaction of lithium hexafluorophosphate with substrate. The preparation method comprises the following steps: 1) under the protection of protective gas, adding lithium hexafluorophosphate into an organic solvent; 2) heating the solution to a dissolving temperature to obtain solution, then dropwise adding tri(trimethylsilane)borate or tri(trimethylsilane)phosphate into the solution, and forming precipitates; and 3) heating the solution to a reaction temperature, stirring at the reaction temperature and reacting, and after the reaction is finished, sequentially filtering, washing and drying precipitates, so that pure lithium difluorophosphate is obtained. The preparation method provided by the invention can be carried out under relatively mild conditions and has relatively high yield of lithium difluorophosphate, and batch production can be carried out without requiring complex operation.

A rechargeable lithium battery includes a positive electrode including a positive active material, a negative electrode and an electrolyte including a lithium salt, an organic solvent and an additive. The positive active material includes a compound represented by Chemical Formula 1, and the additive includes about 0.5 to about 2 parts by weight of lithium difluorophosphate (LiPO2F2) and about 0.5 to about 3 parts by weight of vinylene carbonate, based on 100 parts by weight of the organic solvent.LiaNixCoyMnzO2.  Chemical Formula 1

The invention discloses a method and a device for recycling and harmlessly treating waste lithium ion battery electrolyte. The method comprises the following steps: step I, adequately discharging a waste lithium ion battery, and collecting cells; step II, placing a reaction tank with a solvent onto a magnetic heating stirrer, and carrying out the water-bath heating at the temperature of 50 to 90 DEG C; and step III, soaking the cells in the solvent; step IV: dropwise adding little water into a reaction solution, simultaneously adding lithium phosphate, controlling the stirring speed to be at 200 to 800r / min in the reaction process, wherein the reaction time lasts for 0.5 to 6 hours, generating a solution containing lithium difluorophosphate, introducing inert gas into the reaction tank, generating hydrogen fluoride in the reaction process, absorbing hydrogen fluoride by virtue of an absorption device, and recycling a process product-lithium fluoride by virtue of filtering. By adopting the method and the device, electrolyte salt and an organic solvent resource can be effectively recycled, the resource configuration can be optimized, the reutilization of the resources can be promoted, and energy can be saved.

The invention discloses a preparation method of lithium difluorophosphate. The preparation method comprises the following steps: adding LiPF6 into a carbonic eater turbid liquid of carbonate at the first heating temperature; reacting to obtain the lithium difluorophosphate (LiPO2F2) at the second heating temperature, wherein the second heating temperature is higher than the first heating temperature. The preparation method provided by the invention has the advantages that the process is simple, the cost is low and the prepared product is high in purity.

The invention provides a purification method of lithium difluorophosphate. The purification method comprises the following steps: dissolving a lithium difluorophosphate coarse product in an organic solvent to obtain a coarse product solution; adding alkaline lithium salt into the coarse product solution, and filtering undissolved substances after heating to obtain a filtrate; carrying out evaporation and concentration on the obtained filtrate to remove part of the organic solvent to obtain concentrated liquor; and adding a low polarity organic solvent into the concentrated liquor for crystallization, and then filtering and drying the mixture to obtain a lithium difluorophosphate pure product. By removing acid in the lithium difluorophosphate coarse product with the alkaline lithium salt and filtering impurities, for example, lithium fluoride and excessive alkaline lithium salt, undissolved in the solvent by selecting a proper solvent and adjusting the polarity of the solvent for crystallization, lithium difluorophosphate, the purity of which reaches over 99.9% and the acidity of which is within 70 ppm to meet the using demand of a battery is obtained more simply. The yield of the purification method is over 85%, and the energy consumption is low.

The invention belongs to the field of lithium-ion batteries, and particularly relates to an electrolytic solution and a lithium-ion battery employing the same. The electrolytic solution comprises an organic solvent, an electrolyte and additives, wherein the additives include the additive A and the additive B; the additive A is selected from at least one of a sulfoxide compound, a sulfone compound, a sulphite compound, a sulphate compound and methylene methanedisulfonate; the additive B is selected from lithium difluorophosphate or at least one of the compounds as shown in a formula I. According to the electrolyte solution, DC impedance of the fresh lithium-ion battery and the DC impedance of a cycled battery can be reduced. The formula I is as shown in the specification.

A nonaqueous electrolyte containing a monofluorophosphate and / or a difluorophosphate and a compound having a specific chemical structure or specific properties. The nonaqueous electrolyte can contain at least one of a saturated chain hydrocarbon, a saturated cyclic hydrocarbon, an aromatic compound having a halogen atom and an ether having a fluorine atom.

The invention provides an electrolyte capable of inhibiting gas production of a lithium-ion battery. The electrolyte comprises a lithium salt, an organic solvent and an additive, wherein the additiveis one or a composition of more of lithium difluoroborate, tetrafluoroethylene oxalic acid phosphate lithium, 1,3-propanesulfonate, ethylene sulfate, vinylethylene carbonate, propylene sulfite, vinylene carbonate, 1,4-butane sulfonate lactone, tris(trimethylsilyl) phosphate, fluoroethylene carbonate and lithium difluorophosphate. According to the electrolyte capable of inhibiting gas production ofthe lithium-ion battery, an excellent CEI / SEI film can be formed on the surface of an electrode of the lithium-ion battery, and gas production caused by direct contact of the electrode of the lithium-ion battery and an electrolyte solvent can be well prevented in the pre-charge process, so that gas production of the lithium-ion battery in the pre-charge process can be well inhibited.

The invention relates to a synthesis method of lithium difluorophosphate, belonging to the technical field of lithium battery electrolyte. The synthesis method is characterized by comprising the following steps: respectively adding P2O5, lithium-containing inorganic salt and dried organic solvent into a closed reaction kettle at normal temperature, airtightly stirring and cooling to -50DEG C to 30DEG C, displacing the atmosphere in the kettle three times with dried inert gas, increasing the temperature to 95DEG C-105DEG C after the content of moisture in the kettle is less than 1ppm, boosting pressure to 0.7MPa-0.85MPa; then introducing POF3, reacting for 5-15 hours under stirring, wherein the reaction temperature and pressure are respectively at 60DEG C to 180DEG C, and 0.5MPa to 2.5MPa, and the molar ratio of POF3 to P2O5 to lithium-containing inorganic salt is 1 to (0-1.5) to (1-5); and then filtering to obtain a filtrate, removing solvent, and recrystallizing solid to obtain crystal. The synthesis method has mild conditions, no side reactions appear, the technology process is simple, the product is easily separated and extracted, the moisture and free chlorine values are low, and the purity of the prepared product is high.

The invention provides a method for inhibiting the metal lithium dendritic crystal growth, which is achieved by using electrolyte containing a main lithium salt and an auxiliary lithium salt, whereinthe auxiliary lithium salt is selected from at least one of lithium difluorophosphate and lithium bis(fluorosulfonyl)imide. The method provided by the invention can inhibit the metal lithium dendriticcrystal growth; the stability of a metal lithium negative electrode SEI film is improved, so that the safety of a metal lithium battery is improved.

The invention discloses a superlow-temperature lithium ion battery electrolyte. The electrolyte is prepared from the following raw materials of organic solvents, lithium salt and a film forming additive, wherein the organic solvents comprise carbon disulfide, ethyl butyrate, diglyme and N,N-dimethylformamide; the lithium salt is lithium tetrafluoroborate; the film forming additive consists of vinylene carbonate and any one of ethylene sulfate, lithium difluorophosphate and imidodisulfuryl fluoride. Compared with t traditional carbonate solvents, the electrolyte has the advantages that the melting point of the used organic solvent is very low, and the higher ion conductivity is still maintained at superlow temperature of -40 DEG C; the additive forms a film at the surface of a cathode, andcan form a stable SEI (solid electrolyte interface) film with low impedance, so as to quickly intercalate and de-intercalate the lithium ions at low temperature. The invention also discloses the lithium ion battery using the electrolyte. The lithium ion battery can reach excellent low-temperature discharge and cycle properties under the superlow-temperature environment.

The invention provides high-voltage electrolyte for a lithium ion battery. The high-voltage electrolyte is composed of an electrolyte lithium salt, fluorocarbonate, nitriles, a solvent and an additive, wherein the electrolyte lithium salt is LiPF6 with the concentration of 1.2mol / L-1.6mol / L; a fluorocarbonate solvent accounts for 10%-60% of the total mass of the solvent; the nitriles account for 5%-15% of the total mass of the solvent; a non-aqueous organic solvent accounts for 23%-84.5% of the total mass of the solvent; the additive is lithium difluorophosphate and accounts for 0.5%-2% of the total mass of the solvent. By compounding and combining cyclic fluorocarbonate, straight-chain fluorocarbonate, the nitriles, the additive and the like, the high-voltage heat stability of the electrolyte is prone to improve and the problems that the high-temperature circulating stability of conventional electrolyte is poor and the high-temperature storage is not ideal are improved. Meanwhile, the electrolyte has small viscosity when the materials are matched; the wetting property of an electrode material is facilitated, the liquid injection time of the lithium ion battery is shortened and the rate performance of the battery is improved.

The invention belongs to the technical field of lithium ion batteries and discloses a start-stop battery electrolyte and a lithium ion battery. The electrolyte is prepared from the following components in percentage by mass: 12-20% of lithium salt, 78-85% of a carbonic ester organic solvent and 1-3% of a functional additive. The lithium salt is prepared from the following components: 0.5-16% of lithium hexafluorophosphate and 0.5-18% of lithium bis(fluorosulfonyl)imide. The functional additive comprises at least two of the following components in percentage by mass: 0.3-1.5% of vinylene carbonate, 0.5-1% of ethylene sulfate, 0.5-1% of lithium difluorophosphate and 0.1-0.5% of lithium difluorobisoxalate phosphate. The positive electrode of the lithium ion battery is super nano lithium ironphosphate LFP, the particle size D50 is 0.2-2.0 microns, and the negative electrode of the lithium ion battery is at least one of artificial graphite, natural graphite, mesocarbon microbeads, soft carbon and hard carbon. The start-stop battery electrolyte disclosed by the invention has relatively high conductivity, relatively low interface impedance and relatively good thermal stability, gives consideration to high-temperature and low-temperature performance of the battery, and has outstanding power and cycle performance.

The invention provides a preparation method of difluorophosphate. The preparation method comprises the following steps: (A) mixing a non-aqueous solvent, fluoride salts, and compounds having a structure represented by the formula (I), and stirring to obtain suspension liquid; (B) introducing PF5 gas into the suspension liquid, heating the suspension liquid to carry out reactions, and performing recrystallization to obtain difluorophosphate. In the formula (I), R1 to R6 individually represent H, a C1-C50 hydrocarbyl group, a C1-C50 substituted hydrocarbyl group, or a group having a structure represented by the formula (II); or two or more of R1 to R6 are combined with each other to form a ring structure, in the formula (II), R7 to R9 individually represent H, a C1-C50 hydrocarbyl group, or a C1-C50 substituted hydrocarbyl group, or one or more of R7 to R9 is further substituted by a group having a structure represented by the formula (II).