377 results about "LITHIUM PHOSPHATE" patented technology

The invention relates to a method for preparing a lithium iron phosphate / carbon composite material of a lithium ion battery, which belongs to the technical field of lithium ion batteries. The method for preparing the lithium iron phosphate / carbon composite material of the lithium ion battery comprises the following steps of: 1) preparing a suspending graphene-dispersed aqueous solution system, namely, crushing graphite to 1 to 5 microns, adding the crushed graphite into distilled water or purified water, adding 0.1 to 5 percent of surfactant, heating with stirring the mixed solution to 180 to 250 DEG C in a sealing way, performing stirring for 2 to 6 hours and reducing the temperature; 2) crushing lithium iron phosphate to the particle size of 1 to 5 microns, adding the crushed lithium iron phosphate into the distilled water or the purified water, adding with stirring 0.01 to 1 percent of coupling agent, performing uniform stirring, adding the graphene-dispersed aqueous solution, and performing stirring and filtration; and 3) vacuum-drying solid powder obtained by the filtration, and calcinating the dried solid powder for 2 to 12 hours to obtain the graphene-coated lithium iron phosphate cathode material. The method has the advantages of simple process, high material performance, high conductivity, high bulk density, high compacted density and the like.

The invention discloses a ternary positive electrode material, a preparation method thereof and an electrochemical device. The preparation method comprises the following steps: mixing a continuous ternary precursor, a lithium source and an aluminum source, and carrying out first sintering to obtain a first sintered product; the primary sintering product is subjected to secondary sintering and dispersion, a single-crystal base material is obtained, the base material comprises a plurality of primary particles, the average size of the primary particles ranges from 2 micrometers to 3 micrometers, and the median particle size Dv50 of the primary particles ranges from 3 micrometers to 5 micrometers; mixing the matrix material with an aqueous solution of lithium phosphate, and carrying out wet coating to obtain a coated product; and sintering the coated product for the third time, so that the lithium phosphate forms a coating layer on the surface of the matrix material, and the ternary positive electrode material is obtained. According to the invention, through two-parameter control of the average size and the median particle size of the matrix material and simultaneous aluminum element internal doping and lithium phosphate surface coating of the matrix material, the structural stability and the cycle performance of the ternary positive electrode material are improved and the service life of the ternary positive electrode material is prolonged through a synergistic effect.

The invention relates to a method for preparing lithium dihydrogen phosphate from a lithium-containing solution by using an extraction-reverse extraction technology, an extraction agent adopted in the method comprises a main extraction agent, a synergistic extraction agent and a diluent, the pKa value of the main extraction agent is 2.2-7, the synergistic extraction agent has a P = O group or a cavity diameter of 0.12-0.15 nm, the water solubility of the synergistic extraction agent is less than or equal to 50 mg / L, and the diluent is a diluent. The synergistic extraction factor R of the extraction agent is more than 100, R = Dmix / (D1 + D2), Dmix is the extraction distribution ratio of the main extraction agent to the lithium when the main extraction agent and the synergistic extraction agent are mixed according to the mass ratio of 1: 1-1: 2, D1 is the extraction distribution ratio of the main extraction agent to the lithium, D2 is the extraction distribution ratio of the synergistic extraction agent to the lithium, and the stripping agent is phosphoric acid. According to the method disclosed by the invention, by selecting the main extraction agent and the synergistic extraction agent, on one hand, lithium monohydrogen phosphate and lithium phosphate impurities cannot be generated by reaction when phosphoric acid is adopted for reverse extraction, and on the other hand, higher separation degree on sodium and potassium can be achieved during extraction, so that high-purity lithium dihydrogen phosphate can be efficiently prepared.

The invention relates to a method for preparing lithium phosphate from a lithium-containing solution by using an extraction-reverse extraction technology, an extraction agent adopted in the method comprises a main extraction agent, a synergistic extraction agent and a diluent, the pKa value of the main extraction agent is greater than 12.5, the synergistic extraction agent has a P = O group, a hydroxyl group or a cavity diameter of 0.12-0.15 nm, the water solubility of the synergistic extraction agent is less than or equal to 50 mg / L, the viscosity is less than or equal to 50 mpa.s, and the diluent is a diluent. The synergistic extraction factor R of the extraction agent is more than 100, R = Dmix / (D1 + D2), the Dmix is the extraction distribution ratio of the main extraction agent to lithium when the main extraction agent and the synergistic extraction agent are mixed according to the mass ratio of (1: 1)-(1: 2), the D1 is the extraction distribution ratio of the main extraction agent to lithium, the D2 is the extraction distribution ratio of the synergistic extraction agent to lithium, and the stripping agent is phosphoric acid. According to the method disclosed by the invention, by selecting the main extraction agent and the synergistic extraction agent, on one hand, lithium monohydrogen phosphate and lithium dihydrogen phosphate impurities cannot be generated by reaction when phosphoric acid is adopted for reverse extraction, and on the other hand, sodium and potassium can be separated at a higher degree during extraction, so that high-purity lithium phosphate can be efficiently prepared.

The invention discloses a long-life lithium manganese iron phosphate positive electrode material and a preparation method thereof, and relates to the technical field of lithium ion battery positive electrode materials. The long-life lithium manganese iron phosphate positive electrode material comprises lithium manganese iron phosphate, a middle coating layer and a carbon coating layer, the surface of the lithium manganese iron phosphate is coated with the middle coating layer, the surface of the middle coating layer is coated with the carbon coating layer, the middle coating layer contains metal fluoride and aluminum-containing sinter, and the aluminum-containing sinter comprises aluminum oxide and lithium metaaluminate. The synergistic coating of the middle coating layer and the carbon coating layer can effectively reduce the contact between the positive electrode material and an electrolyte, inhibit the generation of surface side reactions, improve the stability of the electrode material structure, and have low manganese dissolution and excellent cycle life.

The invention discloses splitting, shock excitation and separation integrated equipment for lithium hexafluorophosphate-based electrolyte recovery, and relates to the technical field of lithium hexafluorophosphate-based electrolyte recovery, the splitting, shock excitation and separation integrated equipment comprises a conveying table and a sealing cover, the top of the conveying table is provided with the sealing cover, the top of the conveying table is provided with a position control mechanism, and the position control mechanism comprises a track conveying plate arranged at the top of the conveying table; an abutting block is arranged on a second sliding block installed at the top of the rail conveying plate, and transmission columns are symmetrically welded and fixed to the side of the abutting block. By integrating components such as the position control mechanism, the cutting vibration mechanism and the lifting frame, clamping, girdling, vibration separation and heating recovery of the battery are automatically completed, manual intervention is reduced, the overall battery treatment efficiency is improved, meanwhile, low-temperature baking condensation is adopted subsequently, an organic solvent is sublimated or volatilized under strict temperature control, and the battery quality is improved. And the lithium hexafluorophosphate is recycled through a condensing system, so that subsequent separation of the lithium hexafluorophosphate is facilitated.

The present application discloses a lithium iron manganese phosphate composite material, a preparation method therefor as well as a secondary battery. The lithium iron manganese phosphate composite material sequentially comprises a core, a first coating layer and a second coating layer, wherein the core comprises LixMnyFe1-y-zDzPO4 material, 1≤x≤1.05, 0<y<1, 0≤z<1, and D is a metal element; the first coating layer comprises LiaAlbMcOd material, 0<a≤1, 0<b<1, 0<c<1, 0<d<3, M comprises at least one of Y element, Zr element and Mg element, and the second coating layer comprises carbon. The method for preparing the lithium manganese iron phosphate composite material comprises: providing a core, which comprises a material having a chemical general formula LixMnyFe1-y-zDzPO4; preparing a first coating layer on the outer surface of the core utilizing an atomic layer deposition technology, the first coating layer comprises a material having a chemical general formula LiaAlbMcOd; and preparing a second coating layer on the outer surface of the first coating layer, the second coating layer comprises carbon.

The invention discloses a lithium dihydrogen phosphate extraction preparation and by-product recycling method, and belongs to the technical field of new energy battery material preparation. The method comprises the following steps: carrying out impurity removal pretreatment on a lithium-containing solution, and selectively extracting lithium ions by utilizing a synergistic extraction system; after washing, carrying out reverse extraction by using phosphoric acid or a phosphoric acid solution containing lithium dihydrogen phosphate to obtain high-concentration and low-impurity reverse extraction liquid; and after the strip liquor is subjected to oil removal, a filter cake generated in the system is recycled to adjust the pH value, then alkaline lithium salt is supplemented to accurately adjust the pH value to 4-5, and battery-grade lithium dihydrogen phosphate is obtained through hot filtration, cooling, pressure reduction, evaporation and crystallization. According to the method, the filter cake (containing dilithium hydrogen phosphate, lithium phosphate and the like) generated by hot filtration is innovatively returned to be used for adjusting the pH value, and the crystallization mother liquor is used for replacing process water to be used for preparing the stripping agent, so that cyclic utilization is realized; when sodium ions in the mother liquor are accumulated to exceed the standard, lithium in the mother liquor is further recycled to generate lithium phosphate to return to the system. The method provided by the invention realizes efficient extraction of lithium and direct preparation of battery-grade lithium dihydrogen phosphate, completes in-system closed-loop utilization of all byproducts, has the advantages of short process, high yield, low cost and environmental friendliness, and is suitable for industrial continuous production.

The invention provides a lithium ion battery negative electrode material as well as a preparation method and application thereof. The lithium ion battery negative electrode material is a porous silicon carbon material coated with lithium phosphate. The preparation method is simple and efficient, lithium phosphate salt is uniformly distributed on the surface of the porous silicon carbon material through solvent wet coating, the lithium phosphate salt is decomposed into LiF and LixPyOz through sintering and heating, and LiF and LixPyOz coating layers are generated in situ on the surface of the porous silicon carbon negative electrode material of the lithium ion battery, so that the porous silicon carbon material uniformly coated with LiF and LixPyOz is obtained, the advantages of LiF and LixPyOz are combined, and the porous silicon carbon material has the advantages that the porous silicon carbon material can be used for preparing the lithium ion battery negative electrode material through cooperation of LiF and LixPyOz; the silicon-carbon material prepared by the method has the characteristics of high strength, high stability and high ionic conductivity, can effectively inhibit volume expansion of the silicon-carbon material in the charge-discharge process, block penetration of electrons and reduce capacity loss of the silicon-carbon material in the reaction process, is used for manufacturing a lithium ion battery and remarkably improves the cycling stability of the battery.

The invention discloses a method for extracting lithium from lithium precipitation mother liquor to obtain lithium phosphate, which specifically comprises the following steps of: performing preliminary extraction on the lithium precipitation mother liquor, performing reverse extraction by adopting a composite reverse extraction agent consisting of phosphoric acid and acetylacetone in a molar ratio of (5-15): 1, controlling the pH value of a reverse extraction system to be 5-7, and performing phase splitting to obtain a lithium phosphate wet product; and finally, adding the lithium phosphate wet product into lithium hydroxide for reaction, and filtering to obtain lithium phosphate. According to the method, efficient enrichment of lithium ions in the lithium precipitation mother liquor is achieved through the extraction and reverse extraction processes, meanwhile, through optimization of a reverse extraction system in the reverse extraction process, formation of calcium phosphate impurities is reduced, the extraction purity of lithium is improved, the morphology of lithium phosphate can be regulated and controlled in the reverse extraction process, batch stability is achieved, and the product quality is improved.

The invention discloses a rechargeable lithium battery including a positive electrode. A rechargeable lithium battery may include a positive electrode including a positive electrode active material, a negative electrode including a negative electrode active material, and an electrolyte including a non-aqueous (e.g., water-insoluble) organic solvent, a lithium salt, and an additive represented by Chemical Formula 1. The positive electrode active material may include a lithium iron phosphate-based compound. Chemical formula 1

The invention provides a lithium metal negative electrode protection layer, a preparation method and application thereof, and a lithium metal battery, and relates to the technical field of lithium metal batteries, the protection layer is formed on the surface of a metal lithium foil, and comprises a polymer and an inorganic substance; the polymer comprises polyvinylidene fluoride-hexafluoropropylene; the inorganic substance includes lithium phosphate. The components of the protective layer cooperate with each other, so that lithium dendrites can be physically inhibited, the first discharge specific capacity, the first coulombic efficiency and the cycle performance can be effectively improved, gas can be actively consumed, and the cycle stability and the safety performance of the lithium metal battery can be cooperatively improved from multiple dimensions; the technical problems that an existing protective layer cannot actively eliminate gas, the lithium dendrite inhibiting effect is poor, and the interface stability is poor are solved.

The invention provides equipment and a process for recovering a lithium battery positive electrode material by alkaline roasting of low-grade clay lithium ore, and relates to the technical field of lithium phosphate preparation, the equipment comprises a reaction kettle, a medicament adding mechanism and an inert gas protection mechanism; the medicament adding mechanism comprises a rotating shaft which is vertically and rotatably connected to the interior of the reaction kettle, a driving disc is fixedly arranged on the surface of the rotating shaft, and two sliding blocks are slidably connected to the interior of the driving disc. According to the scheme, a rotating wheel rotates to intermittently extrude and release a medicine feeding hose, so that a sodium carbonate precipitant is pumped into a solution, four driving plates rotate, a guide frame is downwards extruded through a contact wheel, the guide frame downwards extrudes to drive a piston to slide downwards in an air outlet cylinder, nitrogen is conveyed to the position below the solution, and the sodium carbonate precipitant is pumped into the solution. And dosing and inert gas protection are synchronized, so that excessive lithium carbonate impurities caused by reaction of carbon dioxide and high-concentration Li < + > when a sodium carbonate precipitant is put are avoided, and the chemical purity of the product is ensured to meet the requirement of serving as a positive electrode material of a lithium battery.

The utility model provides a structure for improving the bowl loading weight and precision of a lithium iron phosphate kiln, which relates to the technical field of the bowl loading of the lithium iron phosphate kiln, and comprises a support frame, the support frame is positioned below a blanking pipe of a bowl loading machine, the lower surface of the support frame is fixedly connected with a jacking cylinder, and a telescopic rod of the jacking cylinder is fixedly connected with a tray; a sagger is placed on the upper surface of the tray and located below the discharging pipe. Through the arrangement of the clamping air cylinders and the vibration motors, after charging, the clamping air cylinders on the two sides push the fixing blocks to clamp and fix the saggar from the two sides, at the moment, the vibration motors on the fixing blocks are started, the saggar vibrates, materials in the saggar are vibrated, the bridging phenomenon is weakened, the discharging amount is conveniently and accurately controlled, and the discharging efficiency is improved. And the bowl loading machine does not need to be transformed, and is more convenient.

This invention provides a method for recycling lithium iron phosphate battery cathode materials. The method involves mixing the lithium iron phosphate cathode material, calcined under an inert atmosphere, with an alkaline solution of pH 14.2-14.6 at a liquid-to-solid volume ratio of 30-50 mL / g. The mixture is first leached at a first temperature, then at a second temperature. The leachate and iron(III) oxide are separated. The pH of the leachate is adjusted to 11.5-13.5, and the solution is heated to 70-110°C for lithium precipitation. The resulting lithium phosphate and lithium precipitation mother liquor are then separated. The first temperature is 25-45°C, and the second temperature is 5-20°C lower than the first temperature. This invention employs an alkaline leaching-lithium precipitation process, achieving efficient leaching of lithium and phosphorus while simultaneously recovering lithium phosphate and iron(III) oxide through liquid-to-solid ratio control combined with pH and temperature regulation. This invention does not introduce additional lithium precipitation reagents, and the overall process is simple, efficient, and environmentally friendly, making it significant for the sustainable development of the new energy industry.

The invention belongs to the technical field of batteries, and particularly relates to a lithium titanium aluminum phosphate solid-state electrolyte and a preparation method and application thereof, and the chemical formula of the lithium titanium aluminum phosphate solid-state electrolyte is Li < 1 + x > Al < x > Ti < 2-x-y > M < y > (PO4) 3, the lithium aluminum titanium phosphate solid electrolyte is prepared from the following raw materials: a lithium source, a titanium source, a phosphorus source, an aluminum source, an M source and an auxiliary agent, wherein the auxiliary agent is used for promoting the lithium source, the titanium source and part of the phosphorus source to react to form an intermediate product. As the intermediate phase LiTiOPO4 cooperates with M source doping and substitution, Ti < 4 + > can be inhibited from being reduced into Ti < 3 + >, lattice collapse caused by titanium valence change in electrochemical circulation is avoided, and the ionic conductivity is improved; as the LiTiOPO4 intermediate phase is used for synthesizing the titanium aluminum lithium phosphate, the use amount of single phosphoric acid in the secondary sintering process can be reduced, the high-temperature liquid phase reaction is avoided, and the sintered finished product has the advantages of fluffiness and no sagger bonding; in the synthesis and sintering process of the lithium titanium aluminum phosphate, the LiTiOPO4 intermediate phase tends to form a continuous second phase network at the grain boundary of the LiTiOPO4 intermediate phase, so that the grain boundary impedance of the lithium titanium aluminum phosphate can be reduced.

The invention discloses a lithium manganese iron phosphate material with a core-shell structure and a preparation method thereof.The preparation method of the lithium manganese iron phosphate material with the core-shell structure comprises the following steps that 1, a Li source, a Fe source, a Mn source, a P source, a doping element D1 source and a first carbon source are mixed and subjected to ball milling, lithium manganese iron phosphate precursor slurry is obtained, and the precursor slurry is subjected to spray drying, pre-sintering and smashing to obtain lithium manganese iron phosphate powder; preparing a pre-sintered and crushed LMFP primary sintering sample; (2) mixing and ball-milling a Li source, a Fe source, a P source, a doping element D2 source and a second carbon source to obtain lithium iron phosphate precursor slurry; and (3) dispersing the pre-sintered and crushed LMFP primary sintering sample in the lithium iron phosphate precursor slurry, uniformly mixing, spray-drying, and sintering to obtain the lithium manganese iron phosphate material with the core-shell structure. The invention solves the problems of difficult balance of manganese / iron ratio, poor conductivity, serious manganese dissolution and the like of the existing lithium manganese iron phosphate material, and realizes effective balance of energy density and cycle stability.

The present invention discloses a positive electrode active material, a method for manufacturing the same, and a battery. The positive electrode active material includes an inner core containing lithium metal phosphate, a first coating layer covering at least a portion of the surface of the inner core, and a second coating layer covering at least a portion of the surface of the first coating layer. The XRD diffraction peak intensity of the positive electrode active material in the range of diffraction angle 2θ being 35.5°-35.7° is S1. The XRD diffraction peak intensity of the positive electrode active material in the range of diffraction angle 2θ being 24.1°-25.4° is S2. S2 / S1 is (0.005-0.05):1. The XRD diffraction peak intensity of the positive electrode active material in the range of diffraction angle 2θ being 28.8°-29.2° is S3. S3 / S1 is (0.005-0.05):1.

The invention relates to a method for synergistically recycling a photovoltaic waste material and a waste lithium iron phosphate battery positive electrode material, and belongs to the technical field of recycling of photovoltaic waste materials and waste lithium iron phosphate. According to the method, the photovoltaic waste and the waste lithium iron phosphate battery positive electrode material are used as raw materials, and under the vacuum condition, silicon (Si) in the photovoltaic waste is used for reducing the waste lithium iron phosphate battery positive electrode material to generate lithium silicate slag (Li2SiO3 and Li2Si2O5), elemental phosphorus (P4) and ferrosilicon alloy (Si-Fe). According to the method, valuable components in the photovoltaic waste and the waste lithium iron phosphate battery positive electrode material are effectively utilized, and efficient separation and recycling of lithium, iron, phosphorus and silicon are achieved; and the recovery process is simple.

The invention relates to the technical field of resource recycling and high-value utilization of lithium ion batteries, in particular to a technology for generating, recycling or refining metal through an electrolytic method. The invention discloses a method for synthesizing a manganese ferrite magnetic material from a waste lithium manganese iron phosphate positive electrode material. The method comprises the following steps: preparing waste lithium manganese iron phosphate positive electrode powder, an organic binder and a solvent into slurry, and coating the surface of a titanium mesh with the slurry to obtain a positive plate; constructing an electrolytic tank by taking a blank titanium mesh as a negative electrode and a NaOH aqueous solution as an electrolyte, carrying out electrolytic leaching to obtain Li and P elements, concentrating the electrolyte, supplementing a phosphorus source, and adjusting the pH value to recover lithium phosphate; the method comprises the following steps: ultrasonically separating ferromanganese / graphite remained on a titanium mesh, acidizing and dissolving, filtering to remove graphite, adding citric acid into filtrate for gelation, and subsequently calcining to obtain the manganese ferrite magnetic material. According to the method, efficient leaching of Li and P is achieved through electrochemical treatment, Mn and Fe are synchronously converted into high-crystallinity manganese ferrite in a high-valued mode, and the method has the advantages of being environmentally friendly, low in consumption and capable of achieving all-element closed-loop recovery.

This invention provides a lithium iron phosphate cathode material, its preparation method, and its application. The preparation method includes the following steps: (1) mixing ferrous salt and phosphorus source with an alcohol solvent, heating and stirring, and adding a first lithium source solution to obtain a mixed solution; adjusting the pH of the mixed solution to obtain a mixed precursor; (2) mixing a complexing agent, ferric salt, a second lithium source, phosphorus source, and surfactant with water, stirring to form a sol solution; mixing the mixed precursor obtained in step (1) with the sol solution, heating and stirring to obtain a gel precursor; (3) sintering the gel precursor to obtain the lithium iron phosphate cathode material; wherein the mixed precursor includes lithium phosphate and ferrous phosphate. This invention can achieve lithium iron phosphate gradation of different particle sizes through a single production line, improving the uniformity and compaction density of the material, and avoiding performance differences and poor stability between different batches.

The invention provides a composite positive active material and a preparation method thereof, a composite positive plate, a solid-state battery and electric equipment, and relates to the technical field of batteries. According to the composite positive electrode active material, the core of the active material is modified by adopting the lithium phosphate nanoparticles doped with the rare earth elements, so that the problems of structural stability and interface ion transmission of the core of the active material can be solved at the same time; the modified composite positive electrode active material can synchronously realize structural stability, interface optimization and interface side reaction inhibition, so that triple functions of inhibiting the volume expansion of an active material core, improving the interface ion conductivity and blocking transition metal ion diffusion are achieved; furthermore, the energy density, the cycling stability and the safety of the solid-state battery applying the composite positive electrode active material can be improved.

The application provides a positive electrode sheet, a battery and an electric device. The positive electrode sheet comprises a positive electrode current collector and a positive electrode active layer, the positive electrode active layer comprises a nickel-cobalt-manganese ternary material and a manganese iron lithium phosphate material; the X-ray crystal diffraction spectrum of the positive electrode sheet comprises a first characteristic peak with a 2θ angle of 18.67±0.5° and a second characteristic peak with a 2θ angle of 35.58±0.5°, the peak intensity of the first characteristic peak is I1, and the peak intensity of the second characteristic peak is I2; wherein, 13≤I1 / I2≤30, and the mass percentage of Mn 2+ Mn 2+ 4+ Mn 4+ in the positive electrode sheet satisfies 22%≤W Mn 2+ Mn 4+ ≤62%. The positive electrode sheet of the application has high energy density, good cycle performance and rate performance, and low material cost when applied in a battery.​​​​

The invention relates to the technical field of lithium batteries, in particular to a modified lithium iron phosphate positive active material, a preparation method thereof and a lithium battery. The modified lithium iron phosphate positive electrode active material comprises a main crystal phase, a conductive second phase dispersed and distributed at the crystal boundary of the main crystal phase, and a carbon coating layer located on the outer surface and coating the main crystal phase and the conductive second phase; the main crystalline phase material is lithium iron phosphate with an olivine structure; the conductive second phase material is lithium vanadium phosphate; the lithium battery disclosed by the invention adopts a modified lithium iron phosphate positive electrode active material which takes LiFeP as a main crystal phase, coexists with an L (P) conductive second phase and is externally coated with a low-content thin carbon layer, and is matched with a high-temperature stable electrolyte containing lithium difluorophosphate and / or lithium difluoro (oxalato) borate, lithium hexafluorophosphate and organophosphate; the problem of considering high rate and high-temperature storage safety of the lithium battery is solved synergistically from two aspects of a material phase structure and an electrolyte.

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 invention relates to the technical field of batteries, in particular to a battery. Comprising a positive plate and electrolyte, the positive plate comprises a positive current collector and a positive coating, the positive coating on the first surface is provided with a plurality of concave parts, and the positive coating on the second surface is provided with a plurality of convex parts; the positive electrode coating comprises a ternary material; the electrolyte comprises lithium bis (fluorosulfonyl) imide and lithium hexafluorophosphate, and the mass content of the lithium bis (fluorosulfonyl) imide in the electrolyte is greater than that of the lithium hexafluorophosphate; the electrolyte further comprises 1, 3, 6-hexane trinitrile and lithium difluorophosphate, the mass content C3 of the 1, 3, 6-hexane trinitrile in the electrolyte is larger than or equal to the mass content C4 of the lithium difluorophosphate, and the sum of C3 and C4 is larger than or equal to 0.2% and smaller than or equal to 5%. The electrolyte further comprises fluoro-carboxylic ester, and the mass content C5 of the fluoro-carboxylic ester in the electrolyte is 20%-80%. The battery provided by the invention can effectively improve the problem of folding of the pole piece, and has excellent cycle life and high-temperature safety performance.

The invention relates to the technical field of battery preparation, and provides a lithium oxide gradient doped lithium-phosphorus-sulfur-chlorine-oxygen solid electrolyte and a preparation method thereof.The lithium oxide gradient doped lithium-phosphorus-sulfur-chlorine-oxygen solid electrolyte comprises the main components that a lithium oxide concentration gradient exists in the thickness direction of the electrolyte, the molar content of surface layer lithium oxide is 5%-15%, and the molar content of surface layer lithium oxide is 5%-15%; the molar content of lithium oxide in the central layer is 0.5%-3%; wherein 0.05 < = x < = 0.8, and 0.01 < = y < = 0.3. According to the lithium oxide gradient doped lithium-phosphorus-sulfur-chlorine-oxygen solid electrolyte, the lithium oxide concentration gradient is set along the thickness direction of the electrolyte, so that the stress concentration caused by sudden concentration change can be avoided, and the interface layering risk and the longitudinal penetration of lithium dendrites can be inhibited.

The application provides a lithium phosphate-lanthanum phosphate composite coated lithium-rich manganese-based positive electrode material, and a method of adopting an ethanol-water mixed solvent evaporation drying combined with low-temperature sintering to uniformly construct a composite coating layer composed of ion conduction type lithium phosphate and inert stable type lanthanum phosphate on the surface of the lithium-rich manganese-based positive electrode material. The complementary function and the synergistic distribution in space of the lithium phosphate and the lanthanum phosphate together realize the comprehensive modification effect of "no reduction of ion transmission and effective inhibition of side reaction", effectively solve the key technical problems of low first coulomb efficiency, serious voltage attenuation in the cycle process and transition metal dissolution of the lithium-rich manganese-based positive electrode material, and meet the pursuit of people on the comprehensive performance of the high-energy-density lithium ion battery positive electrode material.

The invention provides a preparation method of lithium hexafluorophosphate with low fluorine emission, and relates to the technical field of preparation of lithium hexafluorophosphate, the preparation method comprises the following steps: by taking anhydrous lithium fluoride as a lithium source in a closed reaction kettle, adding a carbonic ester and nitrile mixed organic solvent system, and adding ammonium pentafluorophosphate or an organic complex thereof as a phosphorus-containing precursor, in-situ generation and directional reaction of the fluorine-phosphorus-containing active substance are realized by controlling the slow release rate of the precursor. The solid weakly-alkaline fluorine trapping agent is arranged in the system and can dynamically adsorb or complex generated hydrofluoric acid and other fluorine-containing byproducts, so that fluorine dissipation is reduced. The reaction process is divided into three continuous windows of low-activity pre-reaction, directional main reaction and activity stabilization by regulating and controlling the reaction temperature, the stirring rate and the solvent polarity in stages, so that controllable reaction and uniform conversion of fluorine-containing phosphorus substances are ensured. And after the reaction is finished, gradually carrying out cooling crystallization, solid-liquid separation and drying to obtain a high-purity lithium hexafluorophosphate product. Therefore, generation and emission of hydrofluoric acid are remarkably reduced.

The invention relates to the technical field of hydrogel, in particular to bioactive bionic gradient hydrogel as well as a preparation method and application thereof.The preparation method comprises the following steps: dissolving quaternary ammonium salt chitosan, 3-acrylamidophenylboronic acid, platelet-rich plasma and phenyl (2, 4, 6-trimethylbenzoyl) lithium phosphate in deionized water, stirring until complete dissolution, centrifuging, and drying to obtain a hydrogel solution containing chitosan, 3-acrylamidophenylboronic acid, platelet-rich plasma and phenyl (2, 4, 6-trimethylbenzoyl) lithium phosphate; pre-polymerization liquid is obtained; preparing a tannic acid-iron ion (TA-Fe < 3 + >) mixed solution; adding the pre-polymerized liquid into a mold, and carrying out ultraviolet radiation crosslinking to obtain hydrogel; the hydrogel part is soaked in a tannic acid-iron ion mixed solution, and the gradient hydrogel is obtained. According to the biologically active bionic gradient hydrogel as well as the preparation method and the application thereof, the dual-network hydrogel is soaked in a TA-Fe < 3 + > solution to form a TA-Fe < 3 + > coordinated concentration gradient, so that the hard-to-soft mechanical gradient of tissues such as bone-cartilage, rotator cuff, achilles tendon and the like is accurately simulated.