262 results about "Lithium tetrafluoroborate" patented technology

The invention discloses a synthesizing process for simultaneously obtaining lithium difluoro-oxalato-borate and lithium tetrafluoroborate with favorable performance, which comprises the following steps: (1) leading a fluorine-contained compound, a boron-contained compound, a lithium-contained compound and an oxalate-contained compound to react in a reaction medium at the reaction pressure of 0.1-1MPa and the temperature of 0-100 DEG C, wherein the molar ratio of lithium element, fluorine element, boron element and oxalate ion is (2-3):(5-6):6:2:1; generating reaction liquid containing the lithium difluoro-oxalato-borate and the lithium tetrafluoroborate; (2) carrying out initial separation on the lithium difluoro-oxalato-borate and the lithium tetrafluoroborate in the reaction liquid and then carrying out further extraction separation by an organic solvent which can extract the lithium difluoro-oxalato-borate or the lithium tetrafluoroborate; and (3) respectively carrying out recrystallization and vacuum drying to obtain the battery-grade lithium difluoro-oxalato-borate and the lithium tetrafluoroborate. The invention is suitable for industrially producing two lithium salts which have favorable performance and are used for a lithium ion battery.

The invention discloses low-temperature organic electrolyte taking gamma-butyrolactone as a base solvent and a preparation method thereof. The organic electrolyte comprises a solvent and lithium tetrafluoroborate (LiBF4), wherein the solvent is a mixture of cyclic gamma-butyrolactone, chain carbonic ester and chain carboxylic ester. The organic electrolyte is suitable to be used by a non-graphite-based cathode lithium ion capacitor, a non-graphite-based cathode lithium ion battery and a non-graphite-based cathode lithium ion system. Compared with the formula of the traditional electrolyte, the organic electrolyte greatly improves the low-temperature performance of an electrochemical device and prolongs the cyclic service life of the electrochemical device on the basis of ensuring the electrochemical performance, and meanwhile is favorable for the safety of the electrochemical device; and the formula of the electrolyte is suitable for the non-graphite-based cathode lithium ion capacitor, the non-graphite-based cathode lithium ion battery and the non-graphite-based cathode lithium ion capacitance battery.

The invention relates to a method for preparing an anhydrous lithium tetrafluoroborate which comprises the following steps: a lithium source including lithium hydroxide, lithium carbonate, and the like, reacts with fluorine hydride and boric acid to obtain lithium tetrafluoroborate solution, then the lithium tetrafluoroborate solution is condensed, crystallized and recrystallized, ground, and vacuum dried to obtain the anhydrous lithium tetrafluoroborate. The method of the invention adopts a staged temperature rise control, the process of the preparation is simple, raw materials are cheap and the preparation cost is low, no organic solvent is used during the synthetic process, no poison is produced, therefore, the method accords with the concept of green environmental protection, the anhydrous lithium tetrafluoroborate prepared by the method is determined by a X-ray diffraction map, the diffraction peak is clear and sharp and completely matches the standard card, which shows that the product prepared by the method of the invention is anhydrous LiBF4 with complete crystal form, the quality of the product is equal to the quality of the anhydrous lithium tetrafluoroborate prepared by the reaction of lithium fluoride and boron trifluoride.

The invention relates to a non-aqueous electrolyte and a lithium ion battery using the same. The non-aqueous electrolyte comprises a non-aqueous organic solvent, lithium salts, and an additive, and is characterized in that the additive comprises phosphonic acid cyclic anhydride compounds and lithium tetrafluoroborate, the mass percentage of phosphonic acid cyclic anhydride compounds in electrolyte is 0.05% to 3%, and the mass percentage of lithium tetrafluoroborate in electrolyte is 0.01% to 2%. Compared to the prior art, the lithium ion battery using the electrolyte has the characteristics of excellent low temperature cycle performance and high-rate discharge performance.

The invention provides a high temperature-resistant electrolyte solution of a lithium ion battery. The high temperature-resistant electrolyte solution of the lithium ion battery comprises the raw materials of lithium electrolyte salt, an organic solvent, a high temperature-resistant additive, a film forming additive and a circulatory stability additive, wherein the concentration of the lithium electrolyte salt in the organic solvent is 0.5-2 mol/L; the organic solvent comprises the following components in parts by volume: 5-30 parts of a high-dielectric-constant organic base solvent, 40-65 parts of a high-boiling-point organic solvent, and 5-55 parts of a low-viscosity organic solvent; the high temperature-resistant additive is at least one of lithium tetrafluoroborate, lithium difluoroborate, lithium bis(malonato)borate, lithium bis(oxalate)borate and lithium malonato oxalate borate, the mass of the high temperature-resistant additive accounts for 0.1-8% of the total mass of the electrolyte solution, the mass of the film forming additive accounts for 0.2-4% of the total mass of the electrolyte solution, and the mass of the circulatory stability additive accounts for 0.5-5% of the total mass of the electrolyte solution. According to the invention, the high temperature resistance and circulatory stability of the lithium ion battery are effectively improved.

The invention discloses a low temperature type lithium ion battery electrolyte with high temperature property and lithium ion battery. The electrolyte is made by uniformly mixing and confecting electrolytic salt, non-water organic solvent, alkali additive and film-forming additive, the electrolytic salt is mixed lithium salt made by uniformly mixing lithium tetrafluoroborate and lithium bis(oxalate)borate, and the mol ratio of the two is 96-73: 4-27, the concentration of the mixed lithium salt solution formed by the electrolytic salt and the non-water organic solvent is 0.8-1.2mol/L; the alkali additive is heptamethyldisilazane and the mass ratio of the hepatmethyldisilazane and the non-water organic solvent is 0.1-8%; the mass ratio of the film-forming additive and the non-water organic solvent is 0.1-5%; and the lithium ion battery comprises an anode, a cathode, a diaphragm and low temperature type lithium ion battery electrolyte with high temperature property. The invention has reasonable design, simple preparation method steps and convenient implementation, and the prepared electrolyte and lithium ion battery have favourable comprehensive performances.

PURPOSE: Provided are a non-aqueous electrolyte capable of improving the electrochemical property, and a lithium secondary cell excellent in electrochemical property. CONSTITUTION: The electrolyte comprises a lithium salt; a non-aqueous, organic solvent; and at least one of organic compound selected from compounds of formula 1 to 4(wherein the formula 3 is R9-SO3-Si-(CmH2m+1)3 and formula 4 is CnX2n+1-SO3-Si(CmH2m+1)3). In the formulae, each of R1 to R9 independently represents primary, secondary, or tertiary alkyl group, alkenyl group or aryl group, X is hydrogen or halogen atom, and each of n and m is 0-3. The lithium salt is selected from the group consisting of lithium hexafluorophosphate(LiPF6), lithium tetrafluoroborate(LiBF4), lithium perchlorate(LiClO4), lithium trifluoromethanesulfonate(LiCF3SO3), lithium hexafluoroarsenate(LiAsF6), and mixture thereof.

The invention discloses a preparation method of battery-grade anhydrous lithium tetrafluoroborate. The preparation method comprises the following steps of: making hydrofluoric acid and boric acid react and adding lithium carbonate or lithium hydroxide to obtain a lithium tetrafluoroborate solution; then, filtering, evaporating, concentrating, crystallizing, separating and drying; and adding absolute ethanol to dissolve in a glove box and evaporating the ethanol to obtain a lithium tetrafluoroborate product. The invention improves an aqueous solution method, synthesizes in an inorganic medium, extracts with an organic solvent, further dries to obtain an anhydrous product, overcomes the difficulties in dehydration, extraction and separation because of the inorganic medium and has low cost and convenient operation.

The invention discloses a co-production method for lithium oxalyldifluoroborate and lithium tetrafluoroborate. The co-production method comprises the following steps of: (1) uniformly mixing compounds containing lithium salts and BF3 in an aprotic nonpolar solvent or a solvent with a low aprotic polarity in a molar ratio of (1: 1: 3)-(1: 1.25: 3.75) of lithium to boron to fluorine; (2) refluxing for 1-48 hours at a temperature of 30-100 DEG C, then performing solid-liquid separation, and drying the obtained solid substance to obtain crude products LiODFB and LiBF4; and (3) performing purification and separation on the obtained crude products for one time, or performing purification for many times.

The invention relates to a method for synthesizing an electrolyte lithium salt: lithium difluoro(oxalate)borate. The method comprises the following steps: 1) performing reaction on a silane compound with oxalic acid to obtain a condensation compound of silane and oxalic acid; 2) performing reaction on lithium tetrafluoroborate with the condensation compound of the silane and oxalic acid in a solvent to obtain a crude product; and 3) performing recrystallization on the crude product to the obtain lithium difluoro(oxalate)borate. The synthesizing method not only can be used to obtain the high-purity lithium difluoro(oxalate)borate, but also can effectively reduce the acidity and Cl content of the lithium difluoro(oxalate)borate.

The invention provides a preparation method of high-purity lithium tetrafluoroborate; and the method comprises the following steps that high-purity lithium fluoride and a boron trifluoride coordination compound react in chain carbonate organic solvent, and lithium tetrafluoroborate is obtained after filtration, concentration, extractive crystallization, washing and drying. In the preparation method of high-purity lithium tetrafluoroborate, the boron trifluoride coordination compound has wide sources of raw materials and is low in price, the linear carbonate organic solvent has low toxin and is environment-friendly, the synthetic reaction conditions are mild, the operation is simple, the equipment investment is low, the lithium tetrafluoroborate productivity is high, the yield is high, the energy consumption is low, the post-treatment is simple, and the method is applicable to large-scale production.

The related Li-ion cell fit to discharge at ultra-low temperature comprises an anode, a cathode, a membrane, and the electrolyte. Wherein, the electrolyte comprises: lithium hexafluorophosphate and lithium tetrafluoroborate with weight ratio as 1:5-10:1, and the solvent (including ethylene carbonate, dimethyl carbonate, methyl- ethyl carbonate, and dimethoxyethane). Wherein, the dimethoxyethane is 0.5-10wt%. Compared with prior art, this product can work well at -40deg.

A rechargeable lithium battery includes a positive electrode including a positive active material being capable of intercalating and deintercalating lithium ions; a negative electrode including a negative active material being capable of intercalating and deintercalating lithium ions; and an electrolyte including a non-aqueous organic solvent and a lithium salt. The positive electrode has a positive active mass density of 3.65 g/cc or more, and the lithium salt includes lithium hexafluorophosphate (LiPF₆), lithium tetrafluoroborate (LiBF₄), and a lithium imide-based compound. The rechargeable lithium battery has high capacity, excellent cycle-life, and reliability at a high temperature.

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 a lithium ion battery electrolyte and a lithium ion battery containing the electrolyte. The lithium ion battery electrolyte includes lithium salt, a multi-element organic solvent, a film-forming additive, an SEI film shape modifier and an impregnating additive, the lithium salt is formed by selecting and mixing at least two of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium difluoroborate, lithium imidodisulfuryl fluoride and lithium bis(oxalate)borate, and the concentration of the lithium salt in the electrolyte is 0.75-1.5 mol/L. The lithium ion batteryis long in cycle life, good in high-temperature storage performance and long in cycle life at 55 DEG C, and excellent in low-temperature performance, and meets the requirements for various performances of power batteries in the actual running process of electric buses.

The invention discloses electrolyte for a lithium titanate lithium ion battery. The electrolyte for the lithium titanate lithium ion battery comprises main electrolyte lithium salts, auxiliary electrolyte lithium salts, non-aqueous solvent and additives, wherein main electrolyte lithium salts are lithium hexafluorophosphate, and the concentration of the lithium hexafluorophosphate in the electrolyte is 0.5 to 1.5mol/L; the concentration of the auxiliary electrolyte lithium salts in the electrolyte is 0.005 to 0.5mol/L and the auxiliary electrolyte lithium salts are selected from any one or two or more than two kinds of lithium tetrafluoroborate, lithium bisoxalatoborate, lithium bisfluoroxalatoborate, lithium bis(trifluoromethane sulfonimide) and lithium bis(fluorosulfonyl)imide. According to the electrolyte provided by the invention, the electrolyte lithium salts approximately count for 8 to 15 percent of the total mass percent and are formed by compounding the main electrolyte lithium salts and the auxiliary electrolyte lithium salts; the electrolyte additives are optimized. The lithium titanate lithium ion battery adopting the electrolyte disclosed by the invention has excellent cycle performance, rate performance and high-and-low temperature performance; in addition, an effective interfacial film is formed on a cathode lithium titanate interface, so that the gas expansion phenomenon of the lithium titanate lithium ion battery is greatly relieved.

The invention relates to the technical field of a battery material, and provides a preparation method of an ion liquid crystal/polyimidazole semi-interpenetrating network polymer electrolyte. The method comprises the steps of taking an imidazole liquid (MOBIm-BF4), polyethylene glycol diacrylate (PEGDA), ion liquid crystal ([Cmin]BF4) and lithium tetrafluoroborate (LiBF4) as raw materials, performing ultraviolet irradiation curing to form a film in an organic solvent under a condition that a photoinitiator participates, and obtaining the cross-linked polymerization semi-interpenetrating network solid-state polymer electrolyte after drying, wherein the MOBIm-BF4 can be photo-initiated and polymerized to obtain polyimidazole, and then photo-initiation polymerization is performed after the polyimidazole, the PEGDA, the [Cmin]BF4 and the LiBF4 are mixed, or photo-initiation polymerization is performed on the MOBIm-BF4, the [Cmin]BF4 and the LiBF4 and then photo-initiation polymerization isperformed after the PEGDA is added for mixing. The method is simple and efficient and is suitable for industrial application. The maximum electrical conductivity of the ion liquid crystal/polyimidazole semi-interpenetrating network polymer electrolyte prepared by the method can reach 10<-5>S cm<-1>.

The invention relates to a low-temperature lithium-ion battery, which comprises a positive pole piece, a negative pole piece, a membrane, a low-temperature electrolyte and a housing, wherein each of the positive pole piece and the negative pole piece comprises a positive active material, a negative active material, a binder and a conductive agent; the positive active material is one or a mixture of more of a lithium cobalt oxide, lithium manganate and lithium iron phosphate and accounts for 80%-97% of total mass of a coating of the positive pole piece, the compaction density of the coating is 3.2-3.5 and the single-sided surface density of the coating of the positive pole piece is 50-210g/m<2>; the negative active material is synthetic graphite and accounts for 85%-95% of total mass of the coating of the negative pole piece, the compaction density of the coating is 1.2-1.45, the single-sided surface density of the coating of the negative pole piece is 40-110g/m<2>; and the low-temperature electrolyte is prepared from the following components in percentage by mass: 5%-20% of lithium hexafluorophosphate, 1%-5% of lithium tetrafluoroborate, 20%-30% of ethylene carbonate, 20%-30% of methyl ethyl carbonate, 20%-40% of methyl acetate, 0.5%-2% of glycol sulfite and 0.5%-2% of N,N-dimethyl trifluoroacetamide.