705 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 mixed ion conductor layer for a lithium metal negative electrode, a preparation method of the mixed ion conductor layer and an all-solid-state battery, and belongs to the technical field of sulfide all-solid-state batteries. The preparation method comprises the following steps: synthesizing a sulfide electrolyte 70 (0.75 Li2S-0.25 P2S5)-30LiI through a liquid phase, introducing graphene oxide and a lithium salt precursor 2, 5-dihydroxy-1, 4-benzene diphosphate in the electrolyte preparation process, and carrying out heat treatment and pressing to obtain a mixed ion conductor layer; the graphene oxide can isolate the sulfide electrolyte layer from the lithium metal negative electrode, interface reaction is avoided, and a special porous and interlayer structure provides a transverse growth space for lithium metal deposition. And meanwhile, the lithium diphosphate-based MOF among the graphene layers ensures the rapid movement of lithium ions, enhances the bulk diffusion of lithium at the negative electrode end, reduces the local current density, plays a role in dredging the distribution of the lithium ions, and remarkably prolongs the cycle life of the sulfide all-solid-state battery.

The invention discloses a silicon-carbon composite negative electrode material, a negative electrode plate, a preparation method and application. The silicon-carbon composite negative electrode material is of a double-coating structure and sequentially comprises inner core silicon, a lithium phosphate layer and a fluorine-containing carbon layer from inside to outside, and the mass ratio of the lithium phosphate layer to the inner core silicon is (1-5): 100. When the composite material is applied to a lithium ion battery, the core silicon and the specific double coating layers can improve the fast charging performance and the first effect while optimizing an ion transmission path; a specific double-coating structure can be used as a buffer layer, stress generated by volume expansion of silicon can be released, and pulverization of particles is avoided; and moreover, LiF with high ionic conductivity and higher mechanical strength and an SEI film with more stable regulation and control are formed through reaction with an electrolyte, so that the structural integrity of the material is kept, and the cycle performance of the material is improved.

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 provides equipment and a process for leaching battery-grade lithium phosphate by using waste lithium iron phosphate, and relates to the technical field of resource recovery and battery material preparation, the equipment comprises a support frame, a heating seat, a leaching tank, a driving mechanism and a discharging mechanism; the heating base is installed in the middle of the interior of the supporting frame, the leaching tank is installed on the inner wall of the heating base, an installation cover is installed on the top of the leaching tank in a sealed mode, a main material pipe and an auxiliary material pipe are installed on the two sides of the leaching tank respectively, and a discharging pipe is installed at the bottom end of the leaching tank; the driving mechanism comprises a mounting seat and a motor, the mounting seat is fixedly arranged at the inner bottom of the mounting cover, and the motor is mounted at the top of the mounting seat. According to the scheme, caked industrial-grade sodium phosphate or sodium hydroxide can be crushed into fine particles by adopting rotary grinding, and a reagent can be uniformly dispersed into a purification solution by matching with rotary dispersion blanking, so that the pH of a system and the concentration of sodium phosphate are integrally stable, local reaction abnormity is avoided, and more stable preparation of battery-grade lithium phosphate is ensured.

The invention belongs to the technical field of lithium ion battery positive electrode material preparation, and relates to a manganese-based positive electrode of an all-solid-state battery system, a preparation method and application of the manganese-based positive electrode, the general formula of the manganese-based positive electrode is Li < 1 + x > NiyCoyMn3yOz, the preparation method comprises the following steps: S1, grinding and mixing a lithium-rich manganese original material and lithium phosphate in an inert gas protective atmosphere to obtain a precursor mixture; s2, performing high-energy mechanical ball milling on the precursor mixture; s3, collecting the powder subjected to high-energy mechanical ball milling in an inert gas protective atmosphere to obtain a manganese-based positive electrode material; the manganese-based positive electrode material disclosed by the invention realizes mixed arrangement of part of cations and a double-phase synergistic heterostructure, and has high energy density and voltage, and a halide and sulfide-based all-solid-state battery assembled by using the manganese-based positive electrode material shows good cycling stability and rate capability.

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 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 discloses a manganese iron oxalate precursor, a lithium manganese iron phosphate material and a preparation method and application of the manganese iron oxalate precursor and the lithium manganese iron phosphate material, and belongs to the technical field of battery materials. The lithium manganese iron phosphate material core layer is prepared by taking the oxalate manganese iron precursor with a specific particle size range, particle size distribution uniformity and a specific structure as a raw material, and meanwhile, the shell layer comprising the ionic conductive agent and carbon is introduced outside the core layer, so that the comprehensive performance of the lithium manganese iron phosphate material can be effectively improved; and thus, the capacity, the cycle performance and the first charge-discharge efficiency of the prepared corresponding secondary battery are improved.

The invention provides a method for recovering lithium phosphate from a lithium iron phosphate positive electrode material, which comprises the following steps: carrying out oxidation leaching on the lithium iron phosphate positive electrode material by using an acid solution and an oxidizing agent to obtain a first leaching solution and a first leaching residue; after water is added into the first leaching residues for size mixing, alkali leaching is conducted through sodium hydroxide, second leaching liquid and iron / carbon insoluble residues are obtained, and sodium phosphate crystals are obtained after the second leaching liquid is condensed; carrying out lithium precipitation reaction on the first leaching solution by using the sodium phosphate crystal to obtain lithium phosphate and lithium precipitation residual liquid; the lithium precipitation residual liquid is subjected to concentration and impurity removal, and then is subjected to a bipolar membrane electrodialysis process to obtain an acid solution and sodium hydroxide for reutilization. The invention aims to provide a method for mutually separating lithium, iron and phosphorus aiming at the waste lithium iron phosphate positive electrode material, the method can almost completely recover lithium, iron and phosphorus in the lithium iron phosphate positive electrode material, and the lithium is high in recovery rate and high in purity.

Battery device comprising a thermal insulation element and at least two battery cells arranged along a first direction, wherein the battery cell comprises an electrode assembly and electrolyte solution, the electrode assembly comprising positive electrode plates and negative electrode plates, the positive electrode plate comprising positive current collectors and positive film layers arranged on at least one side of the positive current collectors, the positive film layer comprising lithium phosphate, wherein the negative electrode plate comprises negative current collectors and negative film layers arranged on at least one side of the negative current collector, the negative film layer comprising graphite particles. characterized in that the electrolyte solution comprises fluorosulfonylimide salt, wherein the mass fraction of the fluorosulfonylimide salt in the electrolyte solution is 2% to 12%; wherein the battery cell comprises two first surfaces which are opposite each other along the first direction, wherein the thermal insulation element covers at least one of the two first surfaces and the dimension of the thermal insulation element along the first direction is 0.3 mm to 5 mm.

The invention discloses a method for preparing lithium phosphate with high efficiency and low cost, which comprises the following steps: roasting spodumene concentrate and phosphoric acid, and carrying out slurrying leaching and solid-liquid separation to obtain a lithium dihydrogen phosphate solution; the method comprises the following steps: evaporating and concentrating a lithium dihydrogen phosphate solution, regulating the pH value of the lithium dihydrogen phosphate solution to 7-8 by adopting ammonia water, adding calcium phosphate seed crystals, inducing to remove residual calcium ions and magnesium ions in the solution, and carrying out solid-liquid separation to obtain a phosphate solution containing lithium ions; and then adjusting the pH value back to 11-13 by adopting alkali for lithium precipitation to obtain a lithium phosphate solid, and washing and drying to obtain a battery-grade lithium phosphate product. According to the preparation process of the lithium phosphate, the spodumene is acidized and roasted by adopting phosphoric acid, and pulpified and leached, and calcium ions and magnesium ions in a solution are directly induced by adopting calcium phosphate seed crystals to form crystals to be separated out on the basis of a weakly alkaline condition, so that the process steps are simple and convenient, the subsequent purification procedure is omitted, and the preparation process is more suitable for industrialization; meanwhile, the lithium phosphate product with high purity and high yield can be obtained through the simple and convenient process, the purity can reach 99.5% or above, and the yield can reach 92% or above.

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 a method for separating and recycling phosphorus, iron and lithium in battery black powder, and relates to the technical field of battery recycling. The method comprises the following steps: mixing and leaching battery black powder and sulfuric acid, and filtering to obtain a leaching solution; the pH of the leachate is controlled, ferrous sulfate in the solution is separated out through alcohol substances or ammonium sulfate, and ferrous sulfate precipitates or ammonium ferrous sulfate crystals and mother liquor are obtained after filtration; evaporating and concentrating the mother liquor, adding an impurity removing agent into the mother liquor, and extracting to obtain a phosphoric acid solution and a lithium-containing solution; after phosphoric acid is supplemented into the lithium-containing solution, the pH is adjusted to be 8-10, and battery-grade lithium phosphate precipitates are obtained. According to the method, iron in the leachate is separated out firstly, and the subsequent impurity removal difficulty is greatly reduced, so that recycling of three elements including phosphorus, iron and lithium in the battery black powder is facilitated, and the environmental problem caused by stacking of lithium extraction residues can be avoided.

The invention relates to the technical field of recovery of waste lithium iron phosphate batteries, in particular to a method for preparing battery-grade lithium dihydrogen phosphate by recovering waste lithium iron phosphate batteries. According to the method, lithium iron phosphate positive electrode black powder collected from waste lithium iron phosphate batteries is used as a raw material, and the battery-grade lithium dihydrogen phosphate product is obtained through calcination, oxidation acid leaching, gradient impurity removal, lithium phosphate precipitation, lithium dihydrogen phosphate solution preparation and crystallization drying in sequence. The lithium dihydrogen phosphate prepared by the process has high Li leaching rate and Li recovery rate, and the product content and impurities meet the requirements of battery grade lithium dihydrogen phosphate.

The invention relates to the technical field of lithium zirconium phosphate production, in particular to reaction equipment for preparing layered lithium zirconium phosphate as well as a preparation method and application of the reaction equipment. According to the layered lithium zirconium phosphate preparation method based on the reaction equipment, the reaction equipment comprises a main body, a reaction cavity is formed in the main body; the planetary stirring mechanism is arranged at the top of the reaction cavity; the microwave heating mechanism comprises a central shaft body, a microwave heating assembly and an extension plate; the central shaft body is in driving connection with the planet wheel, and the microwave heating assembly is arranged in the central shaft body; one side of the extension plate is connected with the central shaft body, and the planet wheel drives the central shaft body to rotate so as to drive the extension plate to rotate; the preparation method comprises the following steps: S1, heating and stirring the components in a reaction device in proportion to obtain slurry; and S2, filtering and cleaning the slurry obtained in the step S1, drying and crushing to obtain the layered lithium zirconium phosphate. According to the method, the layered lithium zirconium phosphate can be simply and efficiently obtained at low cost, and the method has good industrial value.

Battery cell, characterized in that it comprises an electrode assembly and an electrolyte solution, wherein the electrode assembly comprises a positive electrode plate, a separating film and a negative electrode plate arranged one above the other, wherein the positive electrode plate comprises a positive current collector and a positive active material layer arranged on at least one side of the positive current collector, wherein the positive current collector comprises a positive current collector section and a positive electrode tab, the positive electrode tab being arranged at at least one end of the positive current collector section along the longitudinal direction of the electrode assembly, wherein the negative electrode plate comprises a negative current collector and a negative active material layer arranged on at least one side of the negative current collector.the negative current collector comprises a negative current collector section and a negative electrode tab, wherein the negative electrode tab is arranged at at least one end of the negative current collector section along the longitudinal direction of the electrode assembly; , wherein the positive active material layer comprises positive active material, the positive active material comprises lithium phosphate with olive stone structure; wherein the positive active material layer has a size of 300 mm to 950 mm along the longitudinal direction of the electrode assembly; wherein the size of the negative active material layer along the longitudinal direction of the electrode assembly is larger than the size of the positive active material layer, the difference between the size of the negative active material layer and the size of the positive active material layer is OH1, wherein OH1 is greater than 1 mm and less than 5 mm, wherein the size of the negative active material layer along the transverse direction of the electrode assembly is larger than the size of the positive active material layer, the difference between the size of the negative active material layer and the size of the positive active material layer is OH2, wherein OH2 is greater than 1 mm and less than or equal to 4 mm; wherein the electrolyte solution in question comprises a solvent and a lithium-containing electrolyte salt, wherein the solvent comprises a carboxylic acid ester solvent and the lithium-containing electrolyte salt comprises a fluorosulfonylimide lithium salt, wherein the mass fraction of the carboxylic acid ester solvent, based on the total mass of the electrolyte solution, is 8% to 57% and the mass fraction of the fluorosulfonylimide lithium salt is 3% to 8%.

The application relates to a cartilage organoid based on a DNA-silk fibroin hybrid hydrogel sustained-release system and a preparation method and application thereof. The DNA-silk fibroin hybrid hydrogel sustained-release system is a hydrogel system after a DNA-silk fibroin hybrid hydrogel sustained-release system premixing solution is printed through a digital light processing system, wherein the DNA-silk fibroin hybrid hydrogel sustained-release system premixing solution contains DNA, silk fibroin, acrylated RGD peptide, acrylated polyethylene glycol NHS ester, glucosamine, TD-198946 and 2,4,6-trimethylbenzoyl lithium phosphate. Compared with the prior art, the glucosamine and TD-198946 introduced in the DNA-silk fibroin hybrid hydrogel sustained-release system can significantly improve the cartilage differentiation efficiency of bone marrow mesenchymal stem cells; and the application can be transplanted to a cartilage defect as a cartilage graft to promote cartilage regeneration and repair.

The invention relates to the technical field of battery recovery, and particularly discloses a recovery method of waste lithium iron phosphate and a lithium ion secondary battery. The recovery method of the waste lithium iron phosphate comprises the following steps: leaching acid liquor, and carrying out solid-liquid separation to obtain acid leaching liquor and a regenerated negative electrode material; cooling and crystallizing, and carrying out solid-liquid separation to obtain first iron-removed slag and first iron-removed liquid; oxidizing, adjusting pH, removing iron, and carrying out solid-liquid separation to obtain second iron-removed slag and second iron-removed liquid; adjusting the pH to precipitate lithium phosphate, and carrying out solid-liquid separation to obtain first lithium phosphate slag and lithium precipitation mother liquor; adding a lithium source into the lithium precipitation mother solution, and carrying out solid-liquid separation after reaction to obtain second lithium phosphate slag and a phosphorus removal solution; and evaporating and concentrating the dephosphorized solution to obtain a by-product salt. By implementing the invention, the recovery of each useful component can be realized.

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 invention discloses a method for preparing battery-grade lithium phosphate and iron phosphate by recycling waste lithium iron phosphate batteries, and belongs to the technical field of lithium ion battery recycling. The method comprises the following steps: mixing and calcining black powder recovered from the waste lithium iron phosphate battery and sodium persulfate; adding water for dissolving, filtering to obtain a water leaching solution A and leaching residues, washing the leaching residues with water, and calcining at high temperature to obtain battery-grade iron phosphate; adding a sodium hydroxide solution into the water extract A, and reacting to obtain a water extract B; adding a trisodium phosphate solution into the water immersion liquid B, performing suction filtration after reaction to obtain lithium phosphate and filtrate, and cleaning and drying the lithium phosphate to obtain battery-grade lithium phosphate; and freezing and denitrifying the filtrate to obtain a denitrified solution, and adding the denitrified solution into the sodium hydroxide solution for recycling. The filtrate is recycled in the whole production process, zero loss of the lithium element is theoretically realized, the iron element is prevented from entering the solution, the preparation steps of the lithium phosphate are simplified, and the method has the advantages of economy and environmental protection.

The invention discloses a double-coating-layer modified graphite negative electrode material and a preparation method and application thereof.The negative electrode material comprises a graphite matrix, the surface of the graphite matrix is sequentially coated with a carbon layer and a lithium phosphate layer, the surface of the graphite matrix is directly coated with the carbon layer, the electronic contact resistance of graphite can be remarkably reduced, and the overall electronic conductivity is improved; the lithium phosphate layer on the outer layer has high lithium ion conductivity (10 <-6 >-10 <-4 > S / cm), can provide a rapid channel for lithium ion migration, and inhibits side reaction of an electrolyte and an electrode material at the same time. Through the double-coating design of the carbon layer and the lithium phosphate layer, the electronic conductivity and the lithium ion migration rate of the graphite negative electrode are synergistically improved, 10-100C high-current discharge is realized, the problem that the two are difficult to take into account by a single coating layer is solved, and the preparation method is simple in process, high in controllability, suitable for industrial production and suitable for industrial production. And when the modified graphite negative electrode is applied to the lithium ion battery, the lithium ion battery has high rate capability and cycling stability and is wide in application range.

The invention relates to the technical field of flexible electronic materials, and discloses a silk fibroin-based topological structure conductive hydrogel and a preparation method and application thereof.The silk fibroin-based topological structure conductive hydrogel is prepared from rGO-coated SilMA serving as a polymerization main body, the rGO-coated SilMA is formed by mixing silk fibroin and graphene oxide dispersion liquid and reacting in the presence of methacrylic acid glyceride, and the rGO-coated SilMA is prepared through the steps that the rGO-coated SilMA serves as the polymerization main body; according to the invention, rGO (at) SilMA is taken as a substrate, polyethylene glycol diacrylate is taken as a reinforcing phase, phenyl-2, 4, 6-trimethylbenzoyl lithium phosphate (LAP) is taken as a photoinitiator, and the mass ratios of all the components in the photocuring ink are as follows: 20% of rGO (at) SilMA, 10% of PEGDA and 0.75% of LAP. The rGO-coated SilMA-PEGDA interpenetrating network structure is constructed and TPMS topological design is introduced, so that the mechanical property and sensing stability of the hydrogel are remarkably improved, the compression modulus is improved by the interpenetrating network, the elongation at break is kept at a high level, the high-deformation scene requirement is met, the stress distribution is more uniform by the negative Gaussian curvature characteristic of the topological structure, and the effective sensing area is increased.

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 relates to a preparation method of a lithium difluoro-bis (oxalate) phosphate concentrated solution, the lithium difluoro-bis (oxalate) phosphate concentrated solution is composed of lithium difluoro-bis (oxalate) phosphate and an aprotic solvent, the aprotic solvent comprises any one or a combination of at least two of diethyl carbonate, ethyl methyl carbonate, ethylene carbonate or propylene carbonate, the concentration of the lithium difluoro-bis (oxalate) phosphate in the lithium difluoro-bis (oxalate) phosphate concentrated solution is 10-35 wt%. The lithium difluoro bis (oxalate) phosphate concentrate provided by the invention exists in a non-proton electrolyte state, so that an evaporative crystallization process is omitted, and the production cost is reduced; the product transportation cost can be reduced through pipeline transportation; and compared with a lithium phosphate solid difluoro bis (oxalate), the process of re-dissolution during use is omitted, the risk of impurity introduction is avoided, and the use cost is reduced.

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 belongs to the field of lithium ion battery positive electrode materials, and particularly relates to a low-cost preparation method of a lithium ion battery positive electrode material lithium manganese iron phosphate. The preparation method comprises the following steps: firstly, reacting manganese oxide with phosphoric acid and hydrogen peroxide in advance to obtain manganese phosphate slurry; adding an iron source and a carboxylic acid-based carbon source into the reaction system, uniformly stirring and mixing, ball-milling for a period of time, adding lithium phosphate and an organic carbon source into the reaction container, fully and uniformly mixing the raw materials, and refining particles; and finally, carrying out spray drying and high-temperature sintering on the obtained slurry to prepare the lithium iron manganese phosphate positive electrode material. The method has the advantages of low slurry viscosity in the preparation process, high solid content, simple preparation process, low cost, easiness in batch and large-scale expansion and the like, and the prepared lithium manganese iron phosphate positive electrode material product has excellent electrochemical performance.

The invention discloses a large-particle-size lithium phosphate material as well as a preparation method and application thereof. The preparation method of the large-particle-size lithium phosphate material comprises the following steps: preparing a lithium source solution, heating half of the lithium source solution to 70-80 DEG C to serve as bottom water, adding a phosphoric acid solution, caustic soda liquid and the rest of the lithium source solution into the bottom water while stirring, adjusting the pH value of the system to 10.5-11 after the addition is completed, and keeping the temperature at 75-80 DEG C to react for 1-2 hours; and filtering and drying reactants to obtain the large-particle-size lithium phosphate. Through innovative flow rate regulation and control and a three-strand parallel flow reaction mode, the technical problems in a traditional lithium phosphate preparation method are successfully solved, and large-particle-size, high-yield and high-efficiency lithium phosphate synthesis under the condition of high-concentration phosphoric acid is realized. The technical scheme provided by the invention has a wide application prospect, and provides effective technical support for industrial production of lithium phosphate.

The invention relates to the technical field of lithium ion battery positive electrode materials, and discloses a double-doped double-coated lithium iron phosphate positive electrode material and a preparation method thereof. The positive electrode material sequentially comprises a Mg < 2 + > and Ti < 4 + > co-doped lithium iron phosphate core, a lithium phosphate ion conductor coating layer and a graphene conducting layer from inside to outside. The preparation method comprises the following steps: mixing raw materials containing iron, phosphorus, lithium, magnesium and titanium sources, and carrying out ball milling, spray drying and two-stage sintering to obtain a doped inner core; and then sequentially carrying out high-pressure rolling pretreatment, lithium phosphate coating heat treatment and graphene chemical vapor deposition on the inner core to finally prepare the positive electrode material. Through the synergistic effect of core co-doping, high-pressure rolling morphology control and a surface double-coating structure, the prepared lithium iron phosphate positive electrode material has high compaction density, conductivity, gram volume under high magnification and cycling stability at the same time.