104results about "Lithium hexafluorophosphate" patented technology

The invention discloses a lithium hexafluorophosphate crystallization and separation device, and relates to the technical field of lithium hexafluorophosphate crystallization and separation, the lithium hexafluorophosphate crystallization and separation device comprises a fixed seat and support legs symmetrically fixed on the periphery of the bottom of the fixed seat, the interior of the fixed seat is fixedly connected with an outer box body, and the lithium hexafluorophosphate crystallization and separation device further comprises an air inlet, an air outlet and an air outlet, an air outlet is formed in the other side of the top of the outer box body; the liquid outlet is formed in the middle of the bottom of the outer box body; the outer barrel body is installed in the outer box body, an inner barrel body is connected to the interior of the outer barrel body in a clamped mode, and a cleaning brush is installed on the lower portion of the partition plate; the swing mechanism is arranged on one side of the outer barrel; and the cleaning mechanism is arranged below the partition plate, and the problems that a lithium hexafluorophosphate solution in the device is in direct contact with the barrel for a long time, so that the barrel is easily corroded and damaged, and large lithium hexafluorophosphate crystals are still possibly contained in the device during discharging, so that the subsequent smooth discharging of the lithium hexafluorophosphate crystals is inconvenient are solved.

The invention discloses a lithium hexafluorophosphate production control system and a method thereof, and relates to the technical field of lithium hexafluorophosphate production, and the method specifically comprises the following steps: obtaining crystallization dynamic information of each area in a reaction kettle in a lithium hexafluorophosphate crystallization process in real time, and analyzing after obtaining to obtain a crystallization dynamic result; respectively generating a crystal growth driving force coefficient and a particle uniform distribution index of each region; constructing a particle size distribution evaluation model for the generated crystal growth driving force coefficient and particle uniform distribution index of each region, generating a particle size distribution coefficient of each region, and performing comprehensive analysis after generation to generate an evaluation coefficient; and analyzing the generated evaluation coefficient, and evaluating the uniformity degree of particle size distribution in the reaction kettle in the lithium hexafluorophosphate crystallization process. The problem of uneven particle size distribution in the lithium hexafluorophosphate crystallization process is solved, and the effect of improving the particle size uniformity and the product quality stability is achieved.

The invention discloses a highly efficient synthesis device for synthesizing lithium hexafluorophosphate, which comprises: a main cavity for containing low-temperature anhydrous hydrofluoric acid; a cover for sealing the main cavity to prevent leakage of gas entering the main cavity; a gas supply convex plate evenly embedded in the side wall of the main cavity, which is an integrated structure with the main cavity and is provided with a plurality of one-way gas delivery valves; a gas delivery device, comprising a gas delivery cavity and a plurality of gas delivery pipelines evenly connected to one side of the gas delivery cavity, the gas delivery cavity being connected to the gas supply convex plate and the one-way gas delivery valve thereon; and a stirring device, comprising a rotating shaft driven by a motor and an impeller arranged on the rotating shaft. The contact area between the gas and the solution is greatly increased, and at the same time, the contact position between the gas and the solution is made more uniform, which solves the problem that the gas in the existing ventilation method is easy to repeatedly contact with the local solution, while reducing the chance of contact with other parts of the solution, resulting in insufficient reaction and reduced synthesis efficiency of lithium hexafluorophosphate.

The invention provides lithium fluoride as well as a preparation method and application thereof. The mass content of carbonate in the lithium fluoride is less than or equal to 1000mg / kg; d10 of the lithium fluoride is smaller than or equal to 10 microns, D50 of the lithium fluoride is smaller than or equal to 20 microns, and the bulk density of the lithium fluoride is 0.9-1.2 g / cm < 3 >. The lithium fluoride provided by the invention has a specific size specification and relatively low carbonate impurity content, and the lithium fluoride is beneficial to preparation of electrolyte salt capable of improving the electrical performance of a battery.

The invention provides a lithium hexafluorophosphate preparation method, which comprises: 1, adding a molecular sieve into an acetonitrile solvent, uniformly shaking, and standing; step 2, filtering the mixture after standing to obtain a treated acetonitrile solvent, and regenerating and recycling the filtered molecular sieve; 3, preparing the dried potassium hexafluorophosphate and the treated acetonitrile solvent, and putting the mixture into a container; 4, stirring the solution in the container, adding lithium hydride in a stirring state, and introducing ammonia gas to carry out catalytic reaction until the reaction is finished; 5, filtering the reactant in the step 4, carrying out reduced pressure distillation on the filtrate, recovering part of the solvent, and carrying out cooling crystallization to obtain a complex of lithium hexafluorophosphate and acetonitrile; and step 6, filtering the complex in the step 5, and carrying out vacuum drying to obtain the lithium hexafluorophosphate. The method provides a green process for preparing the lithium hexafluorophosphate, which integrates safety, economy and environmental protection.

The present invention provides a synthesis system and a synthesis method for lithium hexafluorophosphate. The synthesis system comprises a gas-liquid reaction kettle and a built-in microbubble generation unit provided in the gas-liquid reaction kettle; a material inlet and a gas inlet are formed in the side wall of the gas-liquid reaction kettle; the built-in microbubble generation unit comprises a first microbubble generator and a second microbubble generator, the first microbubble generator is provided below the liquid level in the gas-liquid reaction kettle and connected to the material inlet, and the second microbubble generator is provided at the bottom end of the gas-liquid reaction kettle and connected to the gas inlet; a plurality of layers of perforated plates are successively provided in the gas-liquid reaction kettle from top to bottom; through holes of said perforated plates are staggered, and said perforated plates are provided between the first microbubble generator and the second microbubble generator. The synthesis system of the present invention increases the area of mass transfer between lithium fluoride liquid and phosphorus pentafluoride gas, increases the reaction rate, and reduces energy consumption.

The invention belongs to the technical field of lithium ion battery materials, and particularly relates to a method for preparing lithium hexafluorophosphate from lithium phosphate and hydrogen fluoride, which comprises the following preparation steps: dissolving lithium phosphate in a phosphoric acid aqueous solution to form a mixed solution, and then introducing a mixed gas formed by hydrogen fluoride gas and nitrogen for reaction to obtain lithium hexafluorophosphate. Controlling the feeding molar ratio of the lithium phosphate to the phosphoric acid to the hydrogen fluoride gas to be (1.5-3): 2: (18-20), and after the reaction is completed, decompressing, degassing and concentrating to obtain a mixed crude product of lithium hexafluorophosphate and lithium phosphate; and dissolving the obtained mixed crude product in acetone, carrying out solid-liquid separation, and drying and crystallizing the obtained liquid phase to obtain the high-purity lithium hexafluorophosphate product. According to the method disclosed by the invention, the phosphoric acid aqueous solution is used as a reaction solvent system, meanwhile, the hydrogen fluoride gas is continuously introduced for reaction, and excessive lithium phosphate is adopted for reaction, so that corrosion to reaction equipment can be reduced, side reactions can be reduced, the production safety is improved, and the product yield and quality are improved.

The present invention discloses a continuous production process of liquid lithium hexafluorophosphate, and relates to the technical field of lithium ion battery electrolyte. The whole process of this process is carried out under nitrogen sealing conditions. After liquid anhydrous hydrogen fluoride and liquid chlorine are introduced into a microchannel mixer for mixing, they are introduced into a primary tubular reactor together with phosphorus trichloride liquid for reaction, and the generated gas is introduced into a gas-liquid separator and a condenser to obtain phosphorus pentafluoride gas, which is continuously introduced into a secondary tubular reactor to react with a lithium fluoride solution to generate an unsaturated solution of lithium hexafluorophosphate; the generated lithium hexafluorophosphate solution is adsorbed by a trifluoromethyl hydrogen type macroporous cationic resin, the trifluoromethyl hydrogen type macroporous cationic resin is filtered to remove, the filtrate is crystallized and dried, and the dried lithium hexafluorophosphate crystals are prepared as liquid lithium hexafluorophosphate. This process realizes the continuous production of liquid lithium hexafluorophosphate, improves the safety in the production process, effectively improves the product quality, and meets policy requirements.

The invention relates to the technical field of electrolyte, and discloses a continuous production rotary drying device for lithium hexafluorophosphate, which comprises a furnace body, the left side of the furnace body is fixedly connected with a servo motor, the output end of the servo motor is fixedly connected with a material conveyor, and the left side of the outer wall of the furnace body is provided with a material inlet close to the edge. A nitrogen outlet is formed in the left side of the top of the outer wall of the furnace body, an electric stove wire is fixedly connected to the inner side of the furnace body, the middle of the right side of the furnace body communicates with a nitrogen pipeline, the other end of the nitrogen pipeline communicates with a nitrogen source, and a material outlet is formed in the bottom of the left side of the nitrogen pipeline. According to the lithium hexafluorophosphate drying device, lithium hexafluorophosphate is effectively prevented from being in contact with air to be deteriorated in the drying process by adopting a nitrogen protection device, meanwhile, the stability and consistency of the drying effect are guaranteed by adopting an electric furnace wire heating device, and the manufacturing and maintenance cost is lower than that of other heating modes.

The invention belongs to the technical field of lithium ion battery materials, and particularly relates to a method for synthesizing lithium hexafluorophosphate from lithium tripolyphosphate. The synthesis method comprises the following steps: uniformly mixing lithium tripolyphosphate and phosphorus pentoxide in an ether solvent to obtain a first mixture; introducing a mixed gas of hydrogen fluoride and nitrogen into the first mixture, and carrying out a mixed reaction to obtain a second mixture; and carrying out solid-liquid separation on the second mixture, and carrying out reduced-pressure concentration, recrystallization and reduced-pressure drying on the filtrate after solid-liquid separation to obtain lithium hexafluorophosphate. The lithium tripolyphosphate, the phosphorus pentoxide and the hydrogen fluoride are used as raw materials, the hydrogen fluoride gas is uniformly introduced for reaction, the lithium hexafluorophosphate is directly synthesized in the ether solvent, and the method has the advantages of mild reaction conditions, high reaction efficiency, high product purity and high yield. The problems of more byproducts, high cost and the like in the industrial production process of lithium hexafluorophosphate are solved.

The invention relates to a tank car transporting and conveying system for liquid lithium salt. The preparation method comprises the following steps: adding solid lithium hexafluorophosphate into an organic solvent to prepare a saturated solution of lithium hexafluorophosphate; then adding solid lithium hexafluorophosphate, the prepared saturated solution and a liquid stabilizer into a tank car together to form a supersaturated suspension of lithium hexafluorophosphate in the tank car; transporting the supersaturated suspension of lithium hexafluorophosphate in the tank car to an unloading area, and unloading; the liquid stabilizer disclosed by the invention is prepared by reacting polyether methacrylate PEM-1066, dilithium carbamate phosphate, (Z)-3-tributyltin alkyl acrylate, triethylamine and DMF (Dimethyl Formamide). According to the invention, the material state is a solid-liquid mixed state, the defect of low efficiency of transporting the solid material by a ton bucket is avoided, and more solid lithium hexafluorophosphate can be transported at one time compared with the conventional liquid salt tank car; and compared with traditional liquid salt tank car transportation, the transportation amount is larger, and the transportation cost is saved.

A method for producing phosphorus trifluoride and a method for producing phosphorus pentafluoride, which have high reaction efficiency, low reaction temperature and an excellent energy efficiency. The method includes: a step of introducing phosphorus trichloride and hydrogen fluoride into a first reactor, and a step of discharging phosphorus trifluoride from the first reactor, the first reactor contains carbon material. The method includes a step of introducing the phosphorus trifluoride obtained above and chlorine into a second reactor, and a step of discharging dichloro-phosphorus trifluoride from the second reactor. The method further includes a step of introducing the dichloro-phosphorus trifluoride obtained above and hydrogen fluoride into a third reactor; and a step of discharging phosphorus pentafluoride from the third reactor. The method further includes a step of introducing the phosphorus pentafluoride obtained above and lithium fluoride into a fourth reactor; and a step of discharging lithium hexafluorophosphate from the fourth reactor.

The invention relates to a continuous crystallization system and method of lithium hexafluorophosphate, and belongs to the technical field of lithium ion battery electrolyte production. Aiming at the characteristics and requirements of a lithium hexafluorophosphate cooling crystallization process, the invention provides a continuous crystallization system of lithium hexafluorophosphate, which separates cooling nucleation from cooling crystallization. An ultrasonic generating device is introduced into the cooling nucleation module, lithium hexafluorophosphate is stimulated and induced by ultrasonic waves to nucleate, limitation of a metastable region is reduced, the nucleation rate is increased, crystal nuclei are controlled to be within a small particle size distribution range, meanwhile, introduction of impurities in the nucleation process is reduced, and the product purity is guaranteed. And the lithium hexafluorophosphate solution to be crystallized can continuously and uninterruptedly enter the cooling nucleation module, the cooling crystallization module and the separation circulation module in sequence, so that the continuous crystallization of the lithium hexafluorophosphate is realized, the crystallization time is greatly shortened, and the crystallization efficiency is improved.

The present disclosure discloses a method for recycling a lithium-ion battery electrolyte. After the waste lithium-ion battery is discharged, it is frozen and disassembled to obtain a battery cell containing an electrolyte. The battery cell is immersed in a lithium hydroxide solution containing a catalyst for reaction. The battery cell after the reaction is taken out and washed. The washing solution is mixed with the lithium hydroxide solution after the reaction to obtain a mixed solution. The mixed solution is filtered to obtain a filtrate and a filter residue. The filter residue is reacted with a hydrofluoric acid solution to obtain anhydrous lithium salt. The anhydrous lithium salt is mixed with an organic solution, and PF5 gas is introduced. The mixture is reacted, and filtered to obtain an organic liquid. The organic solution is frozen and filtered to obtain lithium hexafluorophosphate.

A degassing device and method for liquid lithium hexafluorophosphate, the degassing device comprising: a scraper evaporator (E201), a post-degassing concentration and collection tank (V301), a condenser (E202), a solvent collection tank (V303) and a vacuum pump (P103), wherein the scraper evaporator (E201) is connected to a conveying line for raw liquid lithium hexafluorophosphate. The raw liquid lithium hexafluorophosphate is heated by the scraper evaporator (E201) and undergoes a rotational centrifugal force of same; thus, part of the liquid is vaporized, and the vaporized material is conveyed into the condenser (E202). The unvaporized liquid is conveyed to the post-degassing concentration and collection tank (V301). An output end of the condenser (E202) is connected to the solvent collection tank (V303), and a gas-phase output end of the solvent collection tank (V303) is connected to the vacuum pump (P103). Thus, an efficient and excellent degassing effect is achieved, it is ultimately ensured that the content of hydrogen chloride in liquid lithium hexafluorophosphate after a degassing treatment is less than 10 ppm, and the performance of the liquid lithium hexafluorophosphate when used as a component of an electrolyte in lithium ion batteries is also ensured.

The present invention provides a preparation method for co-producing lithium difluorophosphate and lithium hexafluorophosphate, which comprises the following steps: 1) Dissolve lithium phosphate in a carbonate solvent to obtain a lithium phosphate solution, and adjust the temperature of the solution to 5-10 °C; 2) Introduce phosphorus pentafluoride gas into the aforementioned lithium phosphate solution and gradually carry out a reaction to generate lithium difluorophosphate and lithium fluoride. The lithium fluoride continues to react with phosphorus pentafluoride to generate lithium hexafluorophosphate. Finally, the molar ratio of lithium phosphate to phosphorus pentafluoride is 1:2 ± 0.1, and a solution of lithium difluorophosphate and lithium hexafluorophosphate is obtained. Among them, lithium hexafluorophosphate dissolves in the carbonate solution to form a lithium hexafluorophosphate solution, and lithium difluorophosphate is slightly soluble in the carbonate and precipitates in the form of crystals to form a turbid solution; 3) Separate the lithium hexafluorophosphate solution and the lithium difluorophosphate turbid solution. The crystalline lithium difluorophosphate is dried to obtain the finished product, and the concentration of the liquid-phase lithium hexafluorophosphate can be directly adjusted and then enter the electrolyte system.

This invention relates to the field of lithium battery technology and discloses a method for purifying lithium hexafluorophosphate by continuous flow crystallization. The method includes: (1) adding a first organic solvent to crude lithium hexafluorophosphate to dissolve it, preparing a saturated lithium hexafluorophosphate-organic solvent solution, filtering to remove insoluble matter, and obtaining a saturated lithium hexafluorophosphate solution; (2) feeding the saturated lithium hexafluorophosphate solution and the second organic solvent into a microchannel reactor for cooling using metering pumps, filtering the precipitated crystals, washing them with a cooled third organic solvent, and then vacuum drying. The lithium hexafluorophosphate precipitated by the method of this invention has high purity and stable quality, making it very suitable for industrial promotion and application.

The application provides a purification method of lithium fluoride, high-purity lithium fluoride, lithium hexafluorophosphate, an electrolyte and a device, and the purification method of the lithium fluoride comprises the following steps: performing water washing treatment on the lithium fluoride to be purified at 0-50 DEG C to obtain a mixture containing a first solid-phase product; performing ultrasonic treatment on the mixture at 20-25 kHz to obtain a second solid-phase product through filtration; performing fluorination reaction on the second solid-phase product with electronic-grade anhydrous hydrofluoric acid to obtain a third liquid-phase product; performing ion exchange on the third liquid-phase product by using a chelating resin at 0-80 DEG C, and then performing cooling evaporation crystallization, and obtaining a fourth solid-phase product through filtration; and performing cleaning treatment on the fourth solid-phase product by using inert gas at 150-250 DEG C to obtain high-purity lithium fluoride. The high-purity lithium fluoride obtained by the purification method has low content of lithium carbonate and other impurities, and is beneficial to improving the performance and stability of subsequent products.

In the crystallization system of the lithium hexafluorophosphate of the present invention, a first-stage crystallization kettle is connected to a lithium hexafluorophosphate mother liquor supply source through a lithium hexafluorophosphate mother liquor supply line; further connected to the lithium hexafluorophosphate mother liquor supply source through a mother liquor heat exchange line connected with a mother liquor heat exchanger; and further connected to a second-stage crystallization kettle through a first mother liquor delivery line configured to deliver lithium hexafluorophosphate mother liquor, a second-stage crystallization kettle is connected to a third-stage crystallization kettle through a second mother liquor delivery line configured to deliver lithium hexafluorophosphate mother liquor, a third-stage crystallization kettle is connected to a fourth-stage crystallization kettle through a crystalline particle delivery line configured to deliver small crystalline particles in the third-stage crystallization kettle; and further connected to a next process device through a first discharging line, and a fourth-stage crystallization kettle is connected to a next process device through a second discharging line. The crystallization system of lithium hexafluorophosphate of the present invention enables different crystallization stages to be carried out separately in different crystallization kettles, so as to realize continuous feeding and continuous discharging in the course of crystallization.

The invention discloses a lithium hexafluorophosphate purification device convenient to clean, and relates to the technical field of chemical purification equipment, the lithium hexafluorophosphate purification device comprises a base, a vacuum treatment device and an outer cylinder mounted in the middle of the top of the base, the outer cylinder is internally provided with an inner cylinder, one side of the outer cylinder is provided with a mounting plate, and the lithium hexafluorophosphate purification device further comprises a reciprocating motor, the reciprocating motor is fixedly mounted on the upper portion of one side of the mounting plate, the output end of the reciprocating motor is fixedly connected with a main shaft, and the main shaft is fixedly connected with the outer barrel; the cleaning mechanism is arranged in the outer barrel; the buffer mechanism is arranged in the middle of the top of the base and comprises an arc-shaped ring and an arc block, and the problems that part of lithium hexafluorophosphate crystals can be attached to the inner wall of the barrel, are difficult to discharge and are prone to deterioration to generate by-products, and then subsequent vacuum purification treatment of the lithium hexafluorophosphate crystals is troublesome are solved; and the purification precision of the lithium hexafluorophosphate crystal is reduced.

The invention discloses a lithium hexafluorophosphate crystallization separation device, which relates to the technical field of lithium hexafluorophosphate crystallization separation. The device comprises a fixed seat and supporting legs symmetrically fixed around the bottom of the fixed seat, wherein the interior of the fixed seat is fixedly connected with an outer box body, and further comprises: an air inlet, which is installed on one side of the top of the outer box body, and an air outlet is installed on the other side of the top of the outer box body; a liquid discharge port, which is installed in the middle of the bottom of the outer box body; an outer cylinder, which is installed inside the outer box body, and the interior of the outer cylinder is snap-connected with the inner cylinder, and a cleaning brush is installed at the lower part of the partition; a swing mechanism, which is arranged on one side of the outer cylinder; and a cleaning mechanism, which is arranged below the partition, so as to solve the problem that the lithium hexafluorophosphate solution in the device is in direct contact with the cylinder body for a long time, which is easy to cause corrosion damage to the cylinder body, and when the device is discharged, the interior may still contain large pieces of lithium hexafluorophosphate crystals, which is not convenient for the subsequent smooth discharge of the lithium hexafluorophosphate crystals.

A method of producing lithium difluorophosphate, the method including: a step of obtaining a first raw material mixture by mixing lithium hexafluorophosphate, at least one selected from the group consisting of an oxide of phosphorus (A) and a lithium salt of a phosphoric acid (B), and a hydrocarbon solvent having from 6 to 12 carbon atoms; a step of obtaining a second raw material mixture by removing at least a part of the hydrocarbon solvent contained in the obtained first raw material mixture; and a step of producing a crude product containing lithium difluorophosphate by reacting the second raw material mixture.

A method for generating / synthesising a metal hexafluorophosphate is disclosed which comprises dissolving ammonium hexafluorophosphate in tetrahydrofuran (THF) solvent, and flowing the resulting dissol

Provided herein are compositions and methods of manufacturing compositions useful in producing battery electrolyte precursors and battery electrolytes.

This application discloses hexafluorophosphate, phosphorus pentafluoride, and its preparation method and use. This application does not use phosphorus pentafluoride as raw material to prepare hexafluorophosphate, and does not use hydrogen fluoride as raw material to produce phosphorus pentafluoride, reducing the safety risk of production, and uses chemical reagents such as diphosphorus pentaoxide and sulfur trioxide, which have a wide supply source, as raw materials, reducing raw material costs and favoring industrial large-scale production. [Means] The method for preparing the hexafluorophosphate comprises mixing a phosphoric acid solution of diphosphorus pentoxide with sulfur trioxide and a fluoride in an inert gas atmosphere, and after the reaction, sequentially carrying out evaporation concentration, dissolution, filtration and drying to obtain the hexafluorophosphate. The method for preparing the phosphorus pentafluoride using the hexafluorophosphate obtained by the preparation method of the present application comprises mixing the hexafluorophosphate with a catalyst solution, and after the catalytic reaction, sequentially carrying out condensation, pressurization liquefaction and removal of impurities by adsorption to obtain the phosphorus pentafluoride.

The invention discloses a lithium hexafluorophosphate synthesis tail gas comprehensive utilization system and method. The system comprises a tail gas compressor, a tail gas precooler, a gas-liquid separator, a 1 # tower, a partial condenser, a 1 # tower reflux tank, a reboiler, a 2 # tower, an HCl absorption device and a drying device. The tail gas is separated through a gas-liquid separator after being compressed and precooled, a liquid phase enters a 1 # tower for separation, an anhydrous hydrogen fluoride finished product is obtained in a tower kettle, a gas phase at the top of the 1 # tower is subjected to partial condensation, then gas reflux is performed, liquid is sent to the 1 # tower and a 2 # tower respectively, and the gas phase separated by the gas-liquid separator enters the 2 # tower to be in contact with liquid extracted from the top of the 1 # tower in the 2 # tower to recover residual hydrogen fluoride; recycled tail gas is introduced into an HCl absorption device to prepare hydrochloric acid, and nitrogen-containing tail gas is introduced into a drying device to obtain qualified nitrogen which is recycled to a lithium hexafluorophosphate production section. Compared with conventional pressurized rectification, the system has the advantages that the equipment operation pressure and energy consumption are lower, the HF content in the terminal HCl tail gas is lower, a large amount of nitrogen is recycled, and the production cost is reduced.

The invention relates to a safe and environment-friendly treatment method for residues in a tail gas pipeline of a lithium hexafluorophosphate drying process, which comprises the following steps: connecting a tail gas buffer tank in series in the tail gas pipeline of the lithium hexafluorophosphate drying process, and collecting waste materials formed by sedimentation from the tail gas buffer tank; the waste material is treated by the following steps: 1) adding ultrapure water and the lithium hexafluorophosphate waste material into a hydrolysis kettle, hydrolyzing, and extracting hydrofluoric acid through negative pressure azeotropy; 2) centrifuging; centrifugally collecting filtrate as phosphoric acid, and washing a filter cake until effluent is neutral to form crude lithium fluoride; 3) adding ultrapure water and concentrated hydrochloric acid into the crude lithium fluoride; after stirring for 0.5-1 hour, centrifuging to remove iron ions, washing a filter cake with ultrapure water until effluent is neutral, and discharging the filter cake to obtain wet lithium fluoride; and 4) drying the wet lithium fluoride until the moisture is qualified to obtain the lithium fluoride for lithium hexafluorophosphate production.According to the method, the pipeline maintenance cost is reduced, meanwhile, the lithium fluoride and byproducts of hydrofluoric acid and phosphoric acid are recovered from the waste material formed by collection, and the method is environment-friendly and energy-saving.

Provided herein are compositions and methods of making compositions useful in the production of battery electrolyte precursors and battery electrolytes.

The invention belongs to the technical field of electrolyte material preparation, and particularly relates to a method for continuously preparing lithium hexafluorophosphate. The preparation method comprises the following steps: pulping and uniformly mixing excessive liquid PF5 and solid LiF in a pulping kettle, introducing the mixed material into a continuous reactor, controlling the temperature in the reactor to be greater than 18.95 DEG C and the pressure in the reactor to be greater than 3.39 MPa so that the PF5 is in a supercritical state, carrying out stirring reaction, decompressing the reaction material, feeding the reaction material into a spray drying tower, and carrying out solid-gas separation, the solid-phase product is lithium hexafluorophosphate, and the gas-phase component is PF5 which is compressed, condensed and recycled as a reaction raw material. According to the preparation method, the supercritical PF5 serves as a reaction raw material and a heat and mass transfer carrier at the same time, the reaction efficiency can be remarkably improved, other solvents or gas phase components are not introduced, and therefore efficient and high-quality continuous preparation of lithium hexafluorophosphate is achieved.

The invention relates to a preparation process of high-purity lithium hexafluorophosphate, which comprises the following specific steps: S1, quantitatively adding anhydrous hydrogen fluoride into a corresponding reaction kettle body, and controlling the environment temperature in the reaction kettle body at-50 DEG C to-20 DEG C through a temperature control device; s2, maintaining the pressure in the reaction kettle body at 0.1-0.5 MPa, dispersing and adding solid phosphorus pentachloride into the reaction kettle body through a corresponding feeding device, and enabling the solid phosphorus pentachloride to react with the anhydrous hydrogen fluoride in the step S1 at the temperature of-50 DEG C to-20 DEG C to obtain phosphorus pentafluoride and gaseous hydrogen chloride, the gaseous hydrogen chloride escapes from the reaction liquid and then is discharged for recovery or absorption treatment; and S3, dispersing and adding lithium fluoride into the reaction kettle body through the feeding device, and carrying out complexing reaction on the lithium fluoride and phosphorus pentafluoride in the anhydrous hydrogen fluoride to obtain lithium hexafluorophosphate. The reaction process is high in controllability, so that the high-purity lithium hexafluorophosphate product can be stably prepared.