112 results about "Sodium hexafluorophosphate" patented technology

The invention provides a low-temperature electrolyte, positive electrode slurry and a low-temperature sodium ion battery, and belongs to the technical field of battery materials. The low-temperature electrolyte provided by the invention comprises sodium hexafluorophosphate, propylene carbonate, ethylene carbonate, dimethyl carbonate, methyl ethyl carbonate, fluoroethylene carbonate, 2, 2, 3, 4, 4, 4-hexafluorobutyl acrylate and 1, 1, 2, 2-tetrafluoroethyl-2, 2, 3, 3-tetrafluoropropyl ether. The battery provided by the invention comprises the low-temperature electrolyte. The low-temperature electrolyte and the low-temperature sodium-ion battery provided by the invention not only can be compatible with a blended positive electrode material, but also can give consideration to low-temperature performance, ensure that the prepared low-temperature sodium-ion battery has good reaction kinetics and cycle performance, and also can improve the energy density of an electrode and reduce the resistivity of powder.

The invention relates to the technical field of sodium hexafluorophosphate production, and particularly discloses a preparation method of high-purity sodium hexafluorophosphate. Comprising six steps of reaction liquid preparation, preliminary reaction, high-temperature reaction, low-temperature reaction, filtering and washing, drying and the like, ammonium hexafluorophosphate and a vacuum-dried sodium source are respectively put into a tetrahydrofuran (THF) solvent, then an ammonium hexafluorophosphate-THF solution is slowly added into a sodium source-THF suspension drop by drop, the sodium source-THF suspension reacts with the ammonium hexafluorophosphate-THF suspension, and the ammonium hexafluorophosphate-THF suspension is obtained. And white powdery sodium hexafluorophosphate is generated under the control of a high-temperature reflux reaction and a low-temperature reaction, so that the technical problem that the risk of preparation safety is relatively high due to the fact that hydrogen fluoride liquid with strong corrosivity is used when the sodium hexafluorophosphate is prepared in the prior art is solved.

The invention belongs to the technical field of electrolyte, and particularly relates to a method for preparing liquid lithium hexafluorophosphate from sodium hexafluorophosphate. The method comprises the following steps: adding a sodium source into a hexafluorophosphoric acid aqueous solution for neutralization reaction to obtain a sodium hexafluorophosphate aqueous solution, then extracting to remove water, drying to obtain a sodium hexafluorophosphate solid, and heating and decomposing the sodium hexafluorophosphate solid to obtain phosphorus pentafluoride gas; the phosphorus pentafluoride gas is not mixed with SO3, POF3, HF and other impurity gases, a complex refining and purifying process is not needed, and the phosphorus pentafluoride gas with the purity exceeding 99.9% can be obtained after simple purification and can be directly used for synthesizing liquid lithium hexafluorophosphate. The method does not generate waste acid, does not need a complicated phosphorus pentafluoride gas purification process, is particularly suitable for the requirements of the lithium battery industry on high-purity electrolyte, and has the remarkable advantages of high product purity, small environmental pollution, low production cost and the like.

The invention relates to a formula of a high-performance sodium-ion battery electrolyte, and aims to improve the cycle life, safety and rate capability of a sodium-ion battery. The electrolyte comprises sodium hexafluorophosphate as a sodium salt, carbonic ester as an organic solvent and a plurality of additives (fluoroethylene carbonate, bis (2, 2, 2-trifluoroethyl) carbonate, ethylene sulfate, 1, 3-allyl sultone and sodium difluoro (oxalato) borate). Through the synergistic effect of the additives, a stable positive electrode / electrolyte interface film (CEI) is formed, cation dissolution is reduced, and the sodium ion transmission performance and the high-voltage stability of the battery are improved. In a half cell assembled with a NaNi0. 4Fe0. 2Mn0. 4O2 positive electrode, when the electrolyte works in a voltage range of 2-4.2 V, the specific discharge capacity of more than 160mA. H / g is provided, and the capacity retention ratio exceeds 80% after 200 cycles at the rate of 1C.

The invention relates to a sodium ion battery and a nitrile-based electrolyte thereof. The electrolyte comprises: a solvent formed by fluoroethylene carbonate and at least one selected from the group consisting of dinitrile, 3-methoxypropionitrile, isobutyronitrile, valeronitrile, ethylene glycol bis (propionitrile) ether and 4-cyano tetrahydropyran, wherein the volume fraction of fluoroethylene carbonate is 5-20%; and at least one sodium salt selected from the group consisting of sodium hexafluorophosphate, sodium trifluoromethanesulfonate, bis (trifluoromethylsulfonyl) imide sodium and bis (fluorosulfonyl) imide sodium, with a concentration of 2.0-4.0 mol L <-1 >. The electrolyte provided by the invention can simultaneously stabilize an interface between a positive electrode and a negative electrode, and has reasonable ionic conductivity and high electrochemical stability.

The invention discloses a negative-electrode-free sodium battery based on hexagonal boron nitride modified electrolyte and a current collector, and belongs to the technical field of energy storage materials, the electrolyte comprises hexagonal boron nitride h-BN, sodium hexafluorophosphate NaPF6 and diethylene glycol dimethyl ether G2; the concentration of the sodium hexafluorophosphate is 1 mol / L, and the concentration of the hexagonal boron nitride is 150 g / L. And the current collector comprises a conductive agent SuperP, nano dispersed phase hexagonal boron nitride h-BN and a binder polyvinylidene fluoride (PVDF) in a mass ratio of 5: 5: 1, and the blade coating thickness is 20 [mu] m. The negative-electrode-free sodium battery comprises a battery shell, a positive pole piece, an electrolyte, a current collector and a diaphragm located between the positive pole piece and a negative pole piece are arranged in the battery shell, the electrolyte is an organic electrolyte with hexagonal boron nitride, and the current collector is a current collector with a nano dispersed phase. According to the synergistic effect of the current collector and the electrolyte, the problem that the negative-electrode-free sodium battery cannot work under large current is solved.

The invention relates to the technical field of sodium-ion batteries, in particular to a sodium-ion battery non-aqueous electrolyte, a sodium-ion battery, a battery module, a battery pack and a power utilization device.The sodium-ion battery non-aqueous electrolyte comprises sodium salt, an organic solvent and a functional additive, the sodium salt comprises sodium bis (fluorosulfonyl) imide and sodium hexafluorophosphate, and the organic solvent comprises sodium bis (fluorosulfonyl) imide and sodium hexafluorophosphate. The molar ratio of the sodium bis (fluorosulfonyl) imide to the sodium hexafluorophosphate is (8: 2)-(7: 3); the organic solvent is prepared from chain carbonate and cyclic carbonate, and the functional additive is prepared from 2-trifluoromethyl-1, 3-propene sultone and 1-fluoro-2-methyl-ethylene carbonate. According to the invention, the ionic conductivity and thermal stability of the sodium-ion battery electrolyte can be improved through reasonable proportioning and use of the double-ion sodium salt, and meanwhile, corrosion of sodium bis (fluorosulfonyl) imide to an aluminum structural part can also be avoided. The sodium salt and the functional additive cooperate with each other to form an effective interface film on the surface of the electrode, so that the high-temperature storage performance and the high-temperature cycle performance of the sodium ion battery can be remarkably improved.

The invention belongs to the technical field of sodium-ion batteries, and particularly relates to a sodium salt composition, a sodium-ion battery electrolyte and application thereof, and a sodium-ion battery. The sodium salt composition provided by the invention comprises any five or more of sodium bis (trifluoromethanesulfonyl) imide, sodium hexafluorophosphate, sodium difluoro (oxalato) borate, sodium fluoborate, sodium nitrate, sodium perchlorate and sodium difluorophosphate, and the solvation configuration of the sodium ion battery electrolyte prepared from the sodium salt composition is an aggregate with a multi-polar solvation shell layer, and a positive electrode surface solid electrolyte interface film (CEI) and a negative electrode surface solid electrolyte interface film (SEI) which are rich in inorganic matters can be formed, so that the positive electrode and the negative electrode are effectively protected, and the cycling stability and the rate capability of the sodium ion battery are improved.

The invention provides a sodium ion battery without a negative electrode, which adopts sodium ferric phosphate as a positive electrode active material and does not contain a negative electrode active material. According to the negative-electrode-free sodium ion battery, the electrochemical performance, the cycling stability and the safety of the battery are remarkably improved, and the conductivity and the charge transmission efficiency of the positive electrode material are improved. The surface of the negative electrode current collector is roughened, so that the surface area and active sites are increased, and the deposition efficiency and stability of sodium ions are improved. Additives such as sulfamide-grafted nano-diamond are added into the electrolyte, so that the conductivity and the electrochemical stability of the electrolyte are optimized. Meanwhile, by adjusting the concentration of the sodium hexafluorophosphate sodium salt electrolyte, the proportion of the cyclic organic ether solvent and the mass ratio of the small organic molecule additive to the inorganic sodium salt additive, the electrochemical performance and the thermal stability of the battery are improved.

The invention discloses a non-selective sodium-ion battery electrolyte suitable for low temperature and a preparation method thereof, and relates to the field of batteries, and the sodium-ion battery electrolyte is composed of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, vinylene carbonate and sodium hexafluorophosphate. The sodium ion battery low-temperature electrolyte with uniform components is obtained by regulating and controlling the proportion of the basic components and mixing the basic components with the additive with proper content, the freezing point of the electrolyte is reduced, the capacity retention ratio of the battery at low temperature is improved, and a new thought is expected to be provided for widening the low-temperature application scene of the sodium ion battery.

The invention discloses a non-aqueous electrolyte for a sodium ion battery. The non-aqueous electrolyte comprises the following components in parts by weight: 70-85 parts of an organic solvent, 10-20 parts of an electrolyte, 0.5-5 parts of a first film-forming additive and 0.5-5 parts of a second film-forming additive, the first film-forming additive is selected from any one or more of 1, 3-propene sultone, 1, 3-propane sultone, methylene methanedisulfonate and 1, 4-butane sultone, and the second film-forming additive is selected from any one or more of 1, 3-propene sultone, 1, 3-propane sultone, methylene methanedisulfonate and 1, 4-butane sultone; the second film-forming additive is selected from any one or more of fluoroethylene carbonate, vinylene carbonate, ethylene sulfate, vinylene sulfate and ethylene sulfite; the electrolyte is composed of sodium hexafluorophosphate, sodium bis (oxalato) borate, sodium bis (fluorosulfonyl) imide and sodium tetrafluoroborate according to the weight ratio of (14-24): (0-1): (0-1): (0-1). By adding the first film-forming additive and the second film-forming additive, the battery film formation is facilitated, the cycle performance is improved, the service life of the sodium battery can be more effectively prolonged, and the sodium battery can be better applied to the fields of energy storage, low-speed vehicles and passenger vehicles.

An electrolyte solution and a sodium-ion battery. The electrolyte solution comprises a sodium salt, an additive, and an organic solvent, wherein the sodium salt comprises sodium hexafluorophosphate and sodium bis(fluorosulfonyl)imide, and the additive comprises pentaerythritol bicyclic sulfate; and the electrolyte solution comprises: in percentage by mass, 2-15 wt% of sodium hexafluorophosphate, 0.1-20 wt% of sodium bis(fluorosulfonyl)imide, 0.1-5 wt% of pentaerythritol bicyclic sulfate, and the balance being an organic solvent. The electrolyte solution has relatively strong stability in a room-temperature or high-temperature environment, so that stringent environmental requirements in stages of the preparation, transportation, and storage of electrolyte solutions are reduced to a certain extent, the production cost can be effectively controlled, and when the electrolyte solution is applied to a sodium-ion battery, the cycling stability of the battery can be improved.

The invention discloses a sodium-philic current collector and a negative-electrode-free sodium ion battery comprising the same. According to the sodium-philic current collector, carbon-coated aluminum foil is subjected to nitrogen plasma treatment, nitrogen doping sites are formed on a carbon-coated layer, the affinity to sodium can be enhanced, and uniform deposition of sodium is promoted; according to the electrolyte, a cosolvent of diethylene glycol dimethyl ether and tetraethylene glycol dimethyl ether is adopted, sodium hexafluorophosphate, sodium tetrafluoroborate and sodium trifluoromethanesulfonate are compounded, (3-fluorophenyl)-oxoacetonitrile and allyl methyl carbonate are added to serve as electrolyte additives, a weak solvation structure is formed, a solid electrolyte interfacial film rich in boron and fluorine is constructed, and side reactions are inhibited; sodium oxalate is added to the positive electrode as a sodium supplementing agent to make up the loss of active sodium caused by low first charge-discharge efficiency. The invention solves the problems of low first charge-discharge efficiency and poor dendritic crystal growth and cycle stability of the non-anode sodium ion battery, has high energy density and process simplicity, and is suitable for large-scale production.

In order to overcome the defect of lack of a preparation method of sodium monofluorophosphate applied to a battery, the invention provides a preparation method of battery-grade sodium monofluorophosphate, which comprises the following steps: adding phosphorus pentoxide and sodium oxide into a reactor and uniformly mixing; mixing sodium hexafluorophosphate with a polar solvent to obtain a mixed solution; dropwise adding the mixed solution into a reactor, heating after dropwise adding to obtain a crude product, and purifying the crude product to obtain sodium monofluorophosphate. According to the sodium monofluorophosphate product prepared by the preparation method disclosed by the invention, the main content of sodium monofluorophosphate is greater than 98%, and chloride ions are lt; the turbidity is less than or equal to 1NTU, and the chromaticity is 1t; the sodium monofluorophosphate prepared by the method has the advantages that the content of the free acid is less than 50ppm, the water content is less than 200ppm, and the sodium monofluorophosphate can reach the standard of the sodium monofluorophosphate used in the battery industry.

The invention relates to a wide temperature range electrolyte for a sodium battery. The electrolyte comprises a sodium salt and an organic solvent, the sodium salt is one or more of sodium hexafluorophosphate, sodium perchlorate, sodium tetrafluoroborate, sodium bis (fluorosulfonyl) imide, sodium bis (trifluoromethylsulfonyl) imide, sodium trifluoromethanesulfonate, sodium difluoro (oxalato) borate and sodium bis (oxalato) borate, and the organic solvent is one or more of 1, 2-diethoxyethane or 1, 2-diethoxyethane. The invention relates to a combination of 1, 2-diethoxyethane and tetrahydrofuran. The wide-temperature-range electrolyte provided by the invention has the advantages of high boiling point, low freezing point, low viscosity, high ionic conductivity and the like, and the solvation effect of the electrolyte solvent and sodium ions is weak, so that the desolvation energy barrier of the sodium ions is reduced, the desolvation energy and charge transfer resistance of the sodium ions on a positive and negative electrode interface are reduced, and the service life of the electrolyte is prolonged. The electrolyte can significantly improve the high and low temperature charge and discharge performance and cycle performance of the sodium battery, and can safely and stably operate in a wide temperature range of-70-60 DEG C.

The invention belongs to the field of sodium metal batteries, and particularly relates to a sodium metal battery and a high-entropy electrolyte thereof, the electrolyte comprises a high-entropy sodium salt and an ether solvent; the high-entropy sodium salt is a combined sodium salt containing more than four of a sodium salt A and a sodium salt B; wherein the sodium salt A comprises three sodium salts compounded by a formula 1 # imgabs0 # NaBH4 and NaFSI; the sodium salt B comprises at least one of sodium hexafluorophosphate, sodium bis (trifluoromethylsulfonyl) imide, sodium difluoro (oxalato) borate, sodium tetrafluoroborate, sodium nitrate, sodium bis (oxalato) borate, sodium difluorophosphate, sodium silicate and sodium perchlorate. The electrolyte provided by the invention can adapt to the characteristics of a sodium metal battery system, and can meet the application requirements of high magnification and wide temperature range.

The invention discloses a porous composite polymer solid electrolyte, a preparation method thereof and a solid sodium ion battery. The porous composite polymer solid electrolyte is prepared from a deep eutectic solvent, an additive, a polymer solution and a sodium super-ion conductor, the deep eutectic solvent is composed of a sodium ion-containing hydrogen bond receptor and a hydrogen bond donor, wherein the sodium ion-containing hydrogen bond receptor is selected from any one of sodium hexafluorophosphate, sodium tetrafluoroborate, sodium bis (oxalato) borate, sodium difluoro (oxalato) borate, sodium bis (trifluoromethanesulfonyl) imide, sodium bis (fluorosulfonyl) imide, sodium perchlorate, sodium nitrate, sodium chloride and sodium difluorophosphate; the additives are ethylene carbonate and propylene carbonate; the polymer solution is composed of a polymer and an organic solvent; the mass ratio of the sodium super-ion conductor to the polymer is 1: (2-5). The porous composite polymer solid electrolyte disclosed by the invention has excellent ionic conductivity and flame retardance, relatively strong mechanical property and excellent safety.

This invention relates to a sodium-supplementing material capable of simultaneously replenishing active sodium and sodium hexafluorophosphate, and its preparation and application. The sodium-supplementing material comprises the following raw material components by weight percentage: 10-50% elemental phosphorus, 50-90% sodium fluoride, and 1-5% Ketjen Black. Compared with existing technologies, the phosphorus-based bifunctional sodium-supplementing separator and sodium-supplementing cathode provided by this invention not only possess higher theoretical capacity, effectively compensating for irreversible capacity loss during the first cycle of the battery, but also generate NaPF6 in situ under electrochemical conditions through the synergistic reaction of red phosphorus and sodium fluoride, achieving simultaneous replenishment of active sodium and electrolyte sodium salts, thereby improving the initial coulombic efficiency and long-term cycle performance of the battery.

The application relates to the technical field of sodium ion batteries, in particular to a sodium ion battery non-aqueous electrolyte, a sodium ion battery, a battery module, a battery pack, and a power utilization device. The sodium ion battery non-aqueous electrolyte comprises a sodium salt, an organic solvent and a functional additive. The sodium salt comprises sodium bisfluorosulfonylimide and sodium hexafluorophosphate, and the molar ratio of the sodium bisfluorosulfonylimide and the sodium hexafluorophosphate is 8:2-7:3. The organic solvent comprises a chain carbonate and a cyclic carbonate. The functional additive comprises 2-trifluoromethyl-1,3-propylene sulfite and 1-fluoro-2-methyl-vinyl carbonate. The sodium ion battery electrolyte ion conductivity and thermal stability can be improved by reasonably matching and using the dual-ion sodium salt, and the corrosion of sodium bisfluorosulfonylimide to aluminum structural parts can be avoided. The sodium salt and the functional additive are mutually synergistic, an effective interface film is formed on the electrode surface, and the high-temperature storage performance and the high-temperature cycle performance of the sodium ion battery can be remarkably improved.

The invention belongs to the technical field of purification of inorganic compounds, and relates to a purification method of sodium hexafluorophosphate based on a supercritical carbon dioxide-carrying agent system. The method mainly comprises the following steps: (1) pressurizing liquid carbon dioxide, heating, and converting into supercritical carbon dioxide; (2) mixing supercritical carbon dioxide with a carrying agent to form a mixed solvent, and mixing the mixed solvent with the crude sodium hexafluorophosphate at a certain extraction temperature and extraction pressure to form a supercritical carbon dioxide mixture with an extract; (3) heating the supercritical carbon dioxide mixture with the extract, and separating the supercritical carbon dioxide mixture into carbon dioxide gas, entraining agent gas and high-purity sodium hexafluorophosphate; and (4) depressurizing, filtering and condensing the separated carbon dioxide gas to obtain recycled liquid carbon dioxide. According to the method, the purification efficiency can be greatly improved, the production cost is low, and resource waste and loss are reduced.

The application provides a low-temperature electrolyte, a positive electrode slurry and a low-temperature sodium ion battery, and belongs to the technical field of battery materials.The low-temperature electrolyte comprises sodium hexafluorophosphate, propylene carbonate, ethylene carbonate, dimethyl carbonate, methyl ethyl carbonate, fluoroethylene carbonate, 2,2,3,4,4,4-hexafluorobutyl acrylate and 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether.The battery comprises the low-temperature electrolyte.The low-temperature electrolyte and the low-temperature sodium ion battery can not only be compatible with blended positive electrode materials, but also take into account the low-temperature performance, ensure that the prepared low-temperature sodium ion battery has good reaction kinetics and cycle performance, and can also improve the energy density of the electrode and reduce the powder resistivity.

This invention relates to the field of electrochemical energy storage technology, specifically disclosing a locally high-concentration electrolyte and its preparation method. The electrolyte uses methoxytrimethylsilane and 2,2,2-trifluoroethyl methanesulfonate as the base solvent, ethoxy(pentafluoro)cyclotriphosphazene or 1,1,1,3,3,3-hexafluoroisopropyl methyl ether as the functional diluent, and is compounded with specific proportions of sodium bis(trifluoromethanesulfonyl)imide, sodium hexafluorophosphate as the main salt, and vinyl sulfate and siloxane polymer additives. Through the synergistic effect between the components, while ensuring high ionic conductivity and excellent wettability, it also significantly improves the stability of the negative electrode interface, providing key material support for the development of high-energy-density negative electrode-free sodium metal batteries, and showing broad application prospects in large-scale energy storage, portable electronic devices, and other fields.

The invention discloses a zinc ion battery negative electrode, a preparation method thereof and a zinc ion battery. The zinc ion battery negative electrode is obtained by performing heat treatment on zinc foil in a modifier, the modifier is any one or a combination of at least two of ammonium hexafluorosilicate, ammonium hexafluorophosphate, ammonium fluoride, potassium hexafluorosilicate, sodium hexafluorosilicate, sodium hexafluorophosphate and potassium hexafluorophosphate; the heat treatment temperature is 60-80 DEG C. The modifier can form a protective layer on the surface of the zinc foil, corrosion can be inhibited, zinc ion transmission and deposition can be regulated and controlled, and the electrochemical performance of the zinc ion battery can be remarkably improved. And the prepared zinc ion battery has excellent cycle life, long cycle stability and high specific discharge capacity.

This invention discloses a sodium-ion battery electrolyte, belonging to the field of sodium-ion battery technology, comprising an organic solvent, a sodium salt, and additives; the organic solvent includes ethylene carbonate, propylene carbonate, methyl ethyl carbonate, and ethyl acetate; the sodium salt includes sodium hexafluorophosphate and sodium difluorosulfonylimide; the additives include fluoroethylene carbonate, vinylene sulfate, sodium difluorophosphate, sodium difluorooxalate borate, and tris(trimethylsilane)phosphate. The sodium-ion battery electrolyte of this invention, through precise adjustment of the solvent and sodium salt ratio, maintains high conductivity at extremely low temperatures, significantly raising the lower limit operating temperature of the battery to -70°C. Simultaneously, through the synergistic effect of the sodium salt and additives, a high-temperature resistant SEI film rich in inorganic components is formed, reducing side reactions at high temperatures and raising the upper limit operating temperature of the battery to 85°C, achieving a wide temperature range application of the battery from -70°C to 85°C.

The invention discloses a high-voltage sodium ion battery electrolyte for a high-specific-energy O3 type layered oxide positive electrode, and relates to the technical field of sodium ion battery electrolyte preparation. Comprising sodium salt, an organic solvent and an additive, the sodium salt is sodium hexafluorophosphate; the organic solvent is propylene carbonate, diethyl carbonate and ethyl methyl carbonate; the additive comprises a self-cleaning additive and a film-forming additive. The electrolyte is suitable for an O3 type layered oxide positive electrode system with the working voltage as high as 4.2 V. The system has good interface stability, oxidation inhibition capability and whole-process protection mechanism, so that side reaction and gas generation are effectively inhibited, the safety of the sodium ion battery under high voltage is improved, and the cycle life of the sodium ion battery under high voltage is prolonged. And meanwhile, the constructed electrolyte system is reasonable in formula, raw materials are easy to obtain, and good cost control and commercialization amplification prospects are achieved. The problem that an interface of an existing traditional electrolyte is unstable under the high-voltage condition is solved.

The invention relates to a preparation method of sodium difluorophosphate, which comprises the following steps: S1, reacting sodium hexafluorophosphate with cyclic siloxane in an aprotic organic solvent at 50-80 DEG C, and filtering after the reaction to obtain a sodium difluorophosphate crude product and mother liquor; s2, the sodium difluorophosphate crude product is subjected to ultrasonic washing with a washing solvent, a sodium difluorophosphate wet solid is obtained, and the washing solvent is a mixed solvent of tetrahydrofuran and any one of dimethyl carbonate, ethyl acetate and ethylene glycol dimethyl ether; and S3, gradually heating the sodium difluorophosphate wet solid, carrying out vacuum drying, and introducing inert gas at intervals in the drying process for replacement. The method is wide in reaction raw material source, low in price, mild in reaction condition, convenient to operate and easy for industrial production; and the prepared sodium difluorophosphate has high purity and high yield, and can meet the relevant requirements of battery application.

The invention provides a long-life sodium ion battery electrolyte, a sodium ion battery and an electric device. The long-life sodium-ion battery electrolyte comprises sodium salt, an organic solvent and a single-component additive, the sodium salt is sodium hexafluorophosphate; the organic solvent is an ester solvent; the additive is a sulfur unsaturated ester additive; based on the mass of the electrolyte, the use amount of the additive is 0.1-5wt%; based on the volume of the electrolyte, the amount-of-substance concentration of the sodium salt is 0.5-3 mol / L; the conductivity of the electrolyte solution at 25 DEG C is 5-15 mS / cm. The long-life sodium-ion battery electrolyte provided by the invention can effectively inhibit the gas production behavior of the sodium-ion battery in the cycle process, reduce the occurrence of side reactions, and improve the coulombic efficiency and cycle performance of the battery.

The invention discloses an electrolyte based on molecular sieve modification and a negative-electrode-free sodium metal battery, and belongs to the technical field of battery materials, the electrolyte based on molecular sieve modification comprises an organic solution of sodium hexafluorophosphate and a refined and activated 4A molecular sieve; the preparation method of the electrolyte comprises the following steps: adding a refined and activated 4A molecular sieve into an organic solution of sodium hexafluorophosphate to obtain a mixed solution; in the mixed solution, the concentration of the refined and activated 4A molecular sieve is 100-300 mg / mL; and standing the mixed solution, and taking supernate to obtain the electrolyte. According to the method, the 4A molecular sieve is refined and activated and then serves as the electrolyte additive to optimize the electrolyte of the negative-electrode-free sodium metal battery, so that the rate capability and the cycling stability of the negative-electrode-free sodium metal battery can be remarkably improved, and the method has potential application value.

This invention relates to the field of sodium hexafluorophosphate production, and particularly to a sodium hexafluorophosphate production apparatus, comprising a base plate and tanks. Several support columns are arranged at the upper end of the base plate, and three tanks are arranged at equal intervals above the support columns. Adjacent tanks are connected by several arc-shaped support plates. A stirring unit for preliminary mixing of chemical agents is installed in the lower tank. This invention uses a storage unit to store and preliminarily stir hydrogen fluoride and tetrapolyphosphoric acid raw materials. The mixed raw materials are then pumped to the lower tank via a water pump, where the stirring unit further stirs the raw materials. The preliminarily mixed raw materials are then transferred to the middle tank via a transfer assembly and the stirring unit. A water temperature unit regulates the temperature inside the corresponding tank, ensuring thorough mixing of the raw materials.

The invention provides a sodium secondary battery and a power utilization device. The sodium secondary battery comprises a positive pole piece, a negative pole piece, a diaphragm and electrolyte, the electrolyte comprises electrolyte salt and a solvent, the solvent comprises an ether solvent and a nitrile fluoride solvent, the electrolyte salt comprises first electrolyte salt and second electrolyte salt, the first electrolyte salt comprises sodium hexafluorophosphate, and the second electrolyte salt comprises sodium hexafluorophosphate. The second electrolyte salt comprises at least one of sodium tetrafluoroborate, sodium nitrate and sodium trifluoroacetate. The sodium secondary battery provided by the invention has high capacity retention ratio and excellent cycle performance under a low-temperature condition.