622 results about "Lithium chloride" patented technology

The invention relates to the technical field of solid-state electrolytes, and discloses a high-ionic-conductivity solid-state electrolyte, a preparation method thereof and a solid-state battery. The preparation method comprises the following steps: mixing lithium sulfide, lithium chloride, lithium oxide, phosphorus pentasulfide and boron nitride in an inert atmosphere to obtain a mixture; carrying out ball milling on the mixture to obtain precursor powder; and sintering the precursor powder, and dispersing the sintered precursor powder to obtain the high-ionic-conductivity solid electrolyte. The boron element, the nitrogen element and the oxygen element are introduced into a lithium phosphorus sulfur chlorine system as doping elements, lattice parameters of LPSC are changed through the boron element, the rotation rate of a PS4 / BS4 tetrahedron is enhanced, and a lithium ion diffusion channel is optimized, so that the lithium ion transition activation energy of the electrolyte is reduced, the migration rate of lithium ions is increased, and the performance of the electrolyte is improved. Therefore, the solid electrolyte has high ionic conductivity. The introduced nitrogen element and oxygen element can interact with atoms such as sulfur and phosphorus, the electron cloud distribution of anion groups is adjusted, the interaction energy of lithium ions and the anion groups is reduced, the lithium ion transmission performance is further improved, and the electrochemical stability of the anion framework is enhanced. This makes it possible to increase the energy density of an all-solid-state battery when used in a solid-state battery.

This invention discloses a method for leaching lithium iron phosphate mixed powder with iron salts and recovering all components, belonging to the field of battery recycling. The invention uses an iron salt solution to leach the mixed powder, obtaining a lithium-containing leachate and leaching residue. Ferrous ions in the leachate are regenerated into ferric iron through acidification and oxidation, and recycled for leaching the next batch of mixed powder. After reaching a preset number of cycles, the leachate is used for re-leaching multiple batches of leaching residue to improve the lithium leaching rate. Ultimately, a enriched solution containing Li, Fe, Cu, and Al and graphite-containing iron phosphate residue are obtained. Copper is recovered from the enriched solution through iron powder replacement, and a high-purity lithium chloride solution is obtained through extraction and separation, while ferric chloride (recycled) and aluminum chloride crystals are also recovered. The leaching residue is treated with hydrochloric acid to obtain regenerated graphite, and the pH is adjusted with alkali to obtain high-purity iron phosphate. This method achieves full component recovery under mild conditions, reducing separation steps and chemical consumption through a "leaching-regeneration-leaching" cycle mechanism, thus achieving both environmental and economic benefits.

The invention discloses a composite coated graphite negative electrode material, a preparation method thereof and a lithium ion solid-state battery, and belongs to the technical field of lithium ion solid-state batteries, the composite coated graphite negative electrode material comprises a graphite matrix and a composite coating layer, and the composite coating layer comprises an inner layer amorphous lithium chloride and an outer layer nanocrystalline LiF / Li3N composite phase. Mixing graphite, lithium chloride containing crystal water and ammonium fluoride to obtain a mixed material; placing the mixed material in a microwave reaction cavity, heating the mixed material to 600-700 DEG C at the microwave power of 800-1200 W in an H2 / Ar mixed atmosphere, and keeping the temperature for 20-60 minutes; and cooling the sintered mixed material, grinding, and sieving with a 100-300 mesh sieve to obtain the composite coated graphite negative electrode material with a coating layer thickness of 10-50 nm. The invention provides an innovative amorphous LiCl / nanocrystalline LiF-Li3N gradient coating layer design, the performance of the lithium ion battery is remarkably improved by optimizing an ion migration path, enhancing the interface stability and reducing the process cost, and a new engineering way is provided for realizing high magnification and long cycle performance of the sulfide all-solid-state battery.

The invention discloses a method for selectively extracting lithium from a positive electrode material / black powder of a waste lithium ion battery. Performing chlorination transformation on the waste lithium ion battery positive electrode material / black powder to obtain chlorination transformation slag; and then, leaching the chlorination transformation slag with water to obtain a lithium chloride solution and lithium extraction slag. And a lithium chloride solution obtained through primary leaching can be used as a leaching solution to circularly leach the chlorination transformation slag, and after Li < + > in the circulating leaching solution is fully enriched, a lithium precipitation reagent is added into the circulating leaching solution, so that the Li < + > is opened in a lithium salt precipitation form. The method has the advantages of low reaction temperature, high reaction efficiency, high valuable metal yield, low production cost and the like, and has a good application prospect.

The present disclosure provides methods of manufacturing psilocybin and crystalline psilocybin via a reaction of psilocin and tetrabenzylpyrophosphate in the presence of lithium chloride complex Grignard reagent, which is followed by hydrogenation. Methods of producing psilocin from 4-hydroxyindole or 4-acetoxyindole are also provided.

The invention provides a preparation method and application of lithium sulfide. The preparation method comprises the following steps: reacting a lithium source with a sulfur source; the lithium source is a solid lithium-containing substance with the purity of 99% or above and the whiteness of 86 or above; the solid lithium-containing substance is selected from one or more of anhydrous lithium hydroxide, lithium hydroxide monohydrate, lithium carbonate, lithium chloride, lithium bromide and lithium nitrate. According to the method, a solid lithium-containing substance with the purity of 99% or above and the whiteness of 86 or above is used as a lithium source and reacts with a sulfur source, and the ionic conductivity value of the Li6PS5Cl solid electrolyte prepared from the obtained lithium sulfide is stable. Experimental results show that the ionic conductivity can stably reach more than 2mS / cm.

The invention belongs to the technical field of solid-state batteries, and provides a lithium-sulfur-phosphorus-chlorine-bromine solid-state electrolyte, a preparation method thereof and an all-solid-state battery. The preparation method comprises the following steps: mixing lithium sulfide and phosphorus sulfide, and carrying out ball milling to obtain a lithium-sulfur-phosphorus ternary mixture; in protective gas, the lithium-sulfur-phosphorus ternary mixture, lithium chloride and lithium bromide are mixed and then subjected to ball milling, and a lithium-sulfur-phosphorus-chlorine-bromine mixture is obtained; and carrying out heat treatment on the lithium-sulfur-phosphorus-chlorine-bromine mixture in protective gas to obtain the lithium-sulfur-phosphorus-chlorine-bromine solid electrolyte. The lithium-sulfur-phosphorus-chlorine-bromine solid electrolyte provided by the invention not only improves the electrochemical stability, but also maintains the high ionic conductivity characteristic.

The invention provides loofah sponge nanocellulose hydrogel and a preparation method thereof.The preparation method comprises the following steps that anhydrous citric acid, choline chloride and water are mixed to react, and a ternary eutectic solvent is obtained; dispersing loofah sponge purified cellulose in a ternary eutectic solvent, washing and filtering a product to be neutral, dispersing the product in water, and performing ultrasonic treatment to obtain loofah sponge nanocellulose turbid liquid; dissolving sodium lignin sulfonate and lithium chloride in a sodium hydroxide solution to obtain a precursor solution; mixing the loofah sponge nanocellulose suspension with water, polyacrylamide, ammonium persulfate and N, N-methylene bisacrylamide, pouring the precursor solution into the loofah sponge nanocellulose suspension, uniformly stirring the mixture, pouring the mixture into a mold, and sealing the mold; and forming to obtain the loofah sponge nanocellulose hydrogel. The invention also provides an application of the hydrogel. The hydrogel disclosed by the invention has excellent biocompatibility, mechanical property and conductivity, has a wide application prospect in the field of flexible electronics, and is simple in preparation process, low in cost, green and environment-friendly.

The invention relates to the technical field of water adsorption materials, in particular to an aluminum-based MOF composite adsorbent and a preparation method and application thereof.The aluminum-based MOF composite adsorbent is obtained by weighing Al-MOF, adding the Al-MOF into a lithium chloride solution, conducting ultrasonic dispersion, stirring, filtering and drying at the temperature of 80-120 DEG C; adding sodium alginate and carrageenan into deionized water, and stirring to obtain double-network hydrogel; and adding the double-network hydrogel into the aluminum-based MOF adsorbent, uniformly mixing, forming by pelleting equipment to prepare adsorbent particles, and drying the adsorbent particles at the temperature of 80-120 DEG C to obtain the aluminum-based MOF composite adsorbent. According to the invention, Al-MOF, sodium alginate and carrageenan are mixed and molded, so that a high-strength hydrogel network can be obtained, and Al < 3 + > in an MOF skeleton and functional groups in sodium alginate and carrageenan in the dual-network hydrogel are coordinated, so that the network structure is tighter and more stable; the free movement of water molecules in the hydrogel can be effectively limited, so that the swelling property and the mechanical stability of the hydrogel are further adjusted.

The invention belongs to the technical field of coatings, and particularly relates to a composite organic silicon anticorrosive coating and a preparation method thereof.The composite organic silicon anticorrosive coating further comprises the following raw materials in parts by weight besides a solvent: 80-95 parts of phenolic epoxy modified organic silicon resin; 1.4 to 3.5 parts of an amine curing agent; 0.08 part to 0.19 part of lithium chloride; 23 parts to 36 parts of filler; the amine curing agent comprises polyamine. According to the composite organic silicon anticorrosive paint disclosed by the invention, under the action of the amine curing agent containing polyamine and lithium chloride, the phenolic epoxy modified organic silicon resin and the filler are mixed and coated on a metal surface, and cross-linking curing of phenolic epoxy molecular chain extension and cross-linking curing of phenolic epoxy molecular chain branch linkage are uniformly carried out; the composite organic silicon anticorrosive coating with excellent impact resistance, hardness and adhesive force is formed.

The invention discloses a preparation method of a high-performance lithium-phosphorus-sulfur-chlorine solid electrolyte, and relates to the technical field of solid-state lithium batteries. The method comprises the following steps: in an inert atmosphere environment, selecting lithium sulfide, phosphorus pentasulfide, sulfur and lithium chloride as raw materials, carrying out mechanical alloying treatment through a high-energy ball milling method, then promoting crystallization through heat treatment, and finally optimizing the particle size distribution of the material through powder grading. The method provided by the invention can effectively improve the ionic conductivity of lithium phosphorus sulfur chlorine, and the solid electrolyte with good fluidity and stability is obtained.

The invention relates to the technical field of polymer photoelectric materials, in particular to a preparation method of a supramolecular gel electrolyte. The method comprises the following steps: esterifying tetraphenylethylene alcohol and methacryloyl chloride to form tetraphenylethylene methacrylate, and performing staged linear heating polymerization on the tetraphenylethylene methacrylate, 3-(methacrylamido) propyl dimethyl 3-thiopropyl ammonium oxide inner salt, acrylic acid, tetraphenylethylene methacrylate and 4-vinylpyridine under the action of ammonium persulfate to obtain a tetraphenylethylene copolymer. And finally, soaking in a lithium chloride aqueous solution to obtain the supramolecular hydrogel electrolyte. The hydrogel obtained by the invention has high mechanical strength and high ionic conductivity, and is suitable for energy storage devices such as flexible supercapacitors and the like.

The invention discloses a preparation method of lithium trifluoromethanesulfinate, and belongs to the field of lithium ion battery materials. The preparation method of the lithium trifluoromethanesulfinate comprises the following steps: 1, mixing trifluoromethanesulfonyl chloride, lithium sulfite, lithium bicarbonate and a first solvent, and heating to react; 2, dissolving the concentrated crude product in a second solvent, and filtering and separating a lithium sulfate solid; and 3, concentrating the filtrate, adding a third solvent, uniformly stirring, filtering and separating the lithium chloride solid, and concentrating to obtain the lithium trifluoromethanesulfinate. According to the method for preparing the lithium trifluoromethanesulfinate, the yield can reach 94%, the operation is simple, byproducts are easy to separate, and the method is suitable for industrial production. In addition, the obtained by-product lithium sulfate can be used for preparing lithium sulfide, the by-product lithium chloride can be used for preparing solid electrolyte, and resource utilization is achieved.

The invention provides a preparation method of sulfide electrolyte and a solid-state battery. The method comprises the following steps: uniformly mixing lithium sulfide and lithium chloride, and pre-sintering the uniformly mixed substance at the temperature of 600-1000 DEG C to obtain a composite precursor; and uniformly mixing the composite precursor with phosphorus pentasulfide, and sintering the uniformly mixed substance to obtain the sulfide electrolyte. The method is used for achieving the effect of improving the ionic conductivity of the sulfide electrolyte.

The invention relates to a heat transfer printing receiving sheet and a preparation method thereof, and belongs to the technical field of soft label printing. The heat transfer printing receiving piece comprises a printing layer, a heat insulation layer, a base material and a back coating layer which are sequentially arranged from top to bottom. The back coating is prepared from the following raw materials in parts by weight: 13 to 16 parts of first resin, 2 to 3 parts of filler, 0.1 to 0.5 part of polyethylene glycol and 0.01 to 0.05 part of lithium chloride; the heat insulation layer comprises the following raw materials in parts by weight: 9-11 parts of an adhesive and 4-7 parts of hollow particles; the printing layer is prepared from the following raw materials in parts by weight: 19 to 22 parts of second resin, 0.1 to 1 part of aromatic hydrocarbon modified polysiloxane, 0.1 to 1 part of polyethylene glycol and 0.1 to 1 part of polyisocyanate curing agent. The invention also discloses a preparation method of the thermal transfer receiving sheet, and the thermal transfer receiving sheet can prevent thermal fusion between the thermal transfer sheet and the thermal sublimation ribbon even under the condition of high printing speed, is good in demolding property with the thermal sublimation ribbon, is aging-resistant, and can improve the optical density of a printed image.

The invention belongs to the technical field of thermoelectricity, and relates to a preparation method and application of a quasi-solid thermoelectric material capable of realizing humidity stability by means of phase separation regulation, the preparation method comprises the following steps: dissolving a negatively charged hydrophilic monomer, an electrically neutral monomer, a cross-linking agent and a photoinitiator in a solvent to obtain a precursor solution, and carrying out an ultraviolet polymerization reaction to form polyelectrolyte gel; mixing the eutectic solvent with an electrolyte aqueous solution containing redox ion pairs and lithium chloride to obtain a quaternary electrolyte system; and immersing the gel into a quaternary electrolyte system, and fully replacing the internal solution through a diffusion effect to obtain the quasi-solid thermoelectric material with stable humidity. The thermoelectric material has the advantages of excellent Seebeck coefficient, good stability, high mechanical strength, large power density and the like, can supply power to wearable electronic products in an actual humidity fluctuation environment, breaks through the main bottleneck of actual application of quasi-solid ionic thermoelectric materials based on ionized water gel, and is wide in application prospect.

The invention specifically discloses a lithium iron phosphate battery black powder recovery method. The method comprises the following steps: S100, carrying out defluorination pretreatment on lithium iron phosphate battery black powder; s200, introducing excessive chlorine into the defluorinated lithium iron phosphate battery black powder, and performing chloridizing roasting at a first preset temperature to obtain a low-temperature roasting product; s300, the low-temperature roasting product is subjected to water immersion dissolution, and filtrate containing lithium chloride and filter residues are obtained after filtering; s400, introducing excessive chlorine gas into the filter residues, performing chloridizing roasting at a second preset temperature, cooling after roasting is completed, and collecting condensate and residues; and S500, mixing the residues with hydrochloric acid or phosphoric acid, carrying out acid leaching washing, and filtering to obtain graphite. According to the lithium iron phosphate battery black powder recovery method, lithium and carbon in the battery black powder raw material can be effectively recovered, high-purity lithium chloride and graphite products are obtained, and the method has the advantages of being simple in process, few in product impurity and good in economic benefit.

The invention relates to the technical field of hydrogel preparation, in particular to a preparation method of novel biomass hydrogel. The biomass hydrogel prepared by the invention overcomes the problems of poor hygroscopicity and poor recyclability of traditional hydrogel in a low-humidity environment. The cassava starch is oxidized by sodium periodate to prepare dialdehyde starch, so that the hydrophilicity is enhanced; sodium alginate is coated and combined with an epoxy group to covalently bond and fix lithium chloride, so that salt slow release and low-humidity deliquescence are realized; the ink containing the nano carbon material is introduced, so that efficient photo-thermal conversion is realized; meanwhile, after the substances are subjected to three-dimensional crosslinking, a polymer network-shaped gel structure is formed, and gradient drying and rehydration control are combined, so that the porous structure and the mechanical strength are guaranteed. The prepared hydrogel can quickly absorb moisture and efficiently perform photo-thermal evaporation in a low-humidity environment, and is good in recyclability.

The invention discloses a halide electrolyte electrode material, a composite positive electrode, an all-solid-state battery and a preparation method of the all-solid-state battery. The chemical formula of the halide electrolyte electrode material is Li Zr T < c > Cl < d >, the preparation method of the halide electrolyte electrode material comprises the following steps: mixing titanium chloride, zirconium chloride and lithium chloride according to a stoichiometric ratio to obtain precursor powder, and placing the precursor powder in a first protective atmosphere for ball milling to obtain premixed amorphous precursor powder; and placing the premixed amorphous precursor powder in a second protective atmosphere, and calcining at 200-400 DEG C, thereby obtaining the product. And mixing the halide electrolyte with commercial lithium iron phosphate and conductive carbon to obtain the composite positive electrode. The all-solid-state battery assembled based on the positive electrode material shows higher energy density. The material provided by the invention has good structural stability and excellent charge-discharge cycle performance.

The invention provides a diaphragm as well as a preparation method and application thereof, and relates to the technical field of lithium ion battery diaphragm materials. The preparation method of the diaphragm comprises the following steps: S1, uniformly mixing a polyamide solution, lithium chloride and a solvent to obtain a spinning solution, and spinning and chopping the spinning solution to obtain polyamide short fibers; s2, dispersing polyamide short fibers, inorganic ceramic particles and auxiliaries in water to obtain water-based coating slurry; and S3, coating a base membrane with the water-based coating slurry, and drying to obtain the water-based composite membrane. The diaphragm provided by the invention has excellent heat resistance, and is helpful for improving the cycle performance and safety performance of the secondary battery.

The invention provides a process for preparing high-purity lithium sulfide based on industrial waste salt recycling, which comprises the following steps: S1, mixing sulfur-containing waste salt and a waste carbon material, granulating, reducing, calcining, separating and purifying to obtain solid sodium sulfide; s2, mixing and ball-milling the obtained solid sodium sulfide and lithium chloride, adding a mixture of a catalyst and ethanol, and performing catalytic reaction to obtain a lithium sulfide crude product; and S3, purifying and drying the obtained lithium sulfide crude product to obtain the lithium sulfide. The method not only can break through the bottleneck of the existing production route, but also can realize the strategic direction of high-value utilization of bulk solid wastes, and has far-reaching significance for promoting sustainable development and green transformation of the battery industry.

Provided is a method for recovering valuable metals from a positive electrode of waste lithium iron phosphate. The method includes: subjecting a waste lithium iron phosphate battery to discharging and disassembly; subjecting a lithium iron phosphate positive plate obtained by the disassembly to breaking, followed by high temperature treatment; uniformly mixing a product obtained by the high temperature treatment with a carbon material, and roasting a mixture in a high-purity Cl2 atmosphere; subjecting a gas phase product obtained by the roasting to fractional quenching and condensation to recover ferric chloride and aluminum chloride separately; and subjecting a solid phase product obtained by the roasting to water leaching and filtration to obtain a lithium chloride aqueous solution, and then adding sodium carbonate to precipitate lithium carbonate. As a one-step carbothermal chlorination method is adopted in combination with a two-stage quenching and condensation process in the present invention, the use of acidic solutions during recovery of valuable metals from the lithium iron phosphate positive electrode can be avoided, and the use of large amounts of alkaline solutions or extraction agents to separate and recover chlorides step by step is also not required. The method of the present invention has the advantages of a high metal recovery rate, a low comprehensive cost and good economic benefits, social benefits and environmental protection benefits.

The invention relates to the technical field of lithium battery materials, in particular to a method for preparing battery-grade lithium carbonate from waste lithium batteries. The method comprises the following steps: disassembling, crushing and sieving a recycled lithium iron phosphate battery to obtain a crushed lithium battery material; a choline chloride-citric acid mixed solution is adopted to conduct leaching treatment on the crushed materials, and sulfuric acid is added to inhibit leaching of iron and phosphorus ions; filtering to obtain a first filtrate and a first filter residue; adding calcium hydroxide into the first filtrate, and filtering to obtain second filtrate and second filter residues; adsorbing the second filtrate with activated carbon to remove impurities, and filtering to obtain a third filtrate and a third filter residue; adding hydrochloric acid into the third filtrate to obtain a lithium chloride solution; carbonizing and converting the lithium chloride solution into a lithium carbonate solution; and carrying out gradient crystallization treatment on the lithium carbonate solution, pulping with pure water, and drying to obtain the high-purity lithium carbonate finished product. The method overcomes the problems of low lithium recovery rate, complex process, low lithium carbonate purity, large crystal particle size, more impurities and the like of the existing lithium iron phosphate battery.

The invention belongs to the technical field of inorganic salt chemical industry. The invention provides a method for preparing anhydrous lithium chloride by using salt lake brine with low magnesium-lithium ratio, which comprises the following steps: pumping clear salt lake brine with low magnesium-lithium ratio into a plate-and-frame filter press for filtration, and sequentially performing microporous filtration and ultrafiltration on filtrate to obtain primary refined brine; filtering the primary refined brine through a nanofiltration membrane device to obtain secondary refined brine; allowing the secondary refined brine to pass through chelating resin to obtain magnesium-removed brine; mixing the magnesium-removed brine with an alkali solution, adjusting the pH value of the mixed solution, and pumping the mixed solution into a continuous extraction device for solvent extraction to obtain a lithium chloride solution; and evaporating and drying the lithium chloride solution in sequence to obtain an anhydrous lithium chloride product. The anhydrous lithium chloride product is prepared by adopting a nanofiltration membrane separation and solvent extraction combined process, the recovery rate of lithium ions is higher than 80%, the fresh water consumption of 1 ton of lithium chloride product is less than 50 cubic meters, the production cost is low, the chemical units are few, and the automation degree is high.

The invention relates to an adhesion modified ionic conductive hydrogel for temperature and humidity sensing, a preparation method thereof and a storage device. The invention discloses adhesion-modified composite cross-linking ionic conductive hydrogel and a preparation method thereof, and relates to the technical field of polymer composite materials. The preparation method comprises the following steps: carrying out in-situ polymerization on polyvinyl alcohol, acrylamide, acrylic acid, cellulose, lithium chloride, a covalent cross-linking agent and an initiator at 50-60 DEG C by a one-pot method for 4-6 hours to obtain a precursor; carrying out low-temperature freeze-thaw cycle at-20 DEG C or below for 2-4 times; and carrying out polyol solvent exchange twice to obtain the polymer. Through in-situ polymerization covalent cross-linking and cellulose grafting, reversible physical cross-linking and secondary solvent exchange steps, the adhesive property of the hydrogel and the durability of the hydrogel in a low-temperature and natural dry environment can be improved on the basis of improving the mechanical property of the hydrogel, and the hydrogel can be used for assembling flexible stress-strain, temperature and humidity sensors and has wide application prospects. The invention also provides an adhesion modified ion conductive hydrogel storage device used for temperature and humidity sensing.

The invention discloses green leaf-imitated porous hydrogel as well as a preparation method and application thereof, and belongs to the technical field of hydrogel materials. The preparation method of the green leaf-imitated porous hydrogel comprises the following steps: mixing polyvinyl alcohol, tannic acid and a composite pigment in a solid state, and grinding to form uniformly dispersed mixed powder; then spraying a glutaraldehyde solution to the mixed powder, carrying out a cross-linking reaction at room temperature, and washing after the reaction to obtain hydrogel; soaking the hydrogel in a lithium chloride solution, and taking out the hydrogel after soaking to obtain the green leaf-imitated hydrogel with the automatic moisture absorption function; the hydrogel has a porous structure, can automatically absorb moisture and simulate a vegetation spectrum in a 400-2500nm wave band at high precision, is suitable for covering the surface of fabric or equipment so as to simulate the spectrum and thermal characteristics of vegetation, and can be widely applied to the field of infrared camouflage.

The invention discloses an aminated graphene oxide / heterocyclic aramid composite fiber and a preparation method thereof. A raw material selected by amination modified graphene oxide is a heterocyclic aramid diamine monomer which is convenient for industrial production, no auxiliary agent (such as lithium chloride or calcium chloride) is added in the preparation process of the amination modified graphene oxide dispersion liquid, and the amination modified graphene oxide dispersion liquid is added into a polymerization reaction system before the polymerization reaction, so that the preparation process is simple and convenient. The tensile property, compressive property and interfacial property of the composite fiber are improved, and the mechanical property stability of the composite fiber in DMSO, DMF, DMAc and other organic solvents can be improved.

The invention provides a method for extracting lithium carbonate from clay type lithium resources, and relates to the technical field of lithium extraction. The method comprises the following steps: carrying out first mixing on a clay type lithium resource and sodium sulfate, and roasting to obtain a roasted material; the roasted material is subjected to water leaching to obtain first ore pulp; the first ore pulp and sodium hydroxide are secondarily mixed to obtain second ore pulp; carrying out third mixing on the second ore pulp and calcium chloride, and carrying out solid-liquid separation to obtain tempered liquid; carrying out nanofiltration, first reverse osmosis and impurity removal on the conditioned solution to obtain an impurity-removed solution; and carrying out fourth mixing on the impurity-removed solution and the saturated sodium carbonate solution to obtain lithium carbonate. According to the method, sodium sulfate serves as an auxiliary agent to achieve selective efficient extraction of lithium in the clay type lithium ore, then lithium sulfate in second ore pulp is converted into lithium chloride through calcium chloride, and the obtained tempered liquid is suitable for a nanofiltration-reverse osmosis process.

The invention is applicable to the technical field of fuel cells, and provides a blending modified polybenzimidazole proton exchange membrane and a preparation method thereof, and the preparation method comprises the following steps: S1, preparing 4-methyl-N-toluenesulfonyl benzene sulfonamide; s2, preparing 4, 4 '-[imino bis (sulfonyl)] dibenzoic acid; s3, preparation of PSI: dissolving CBSI and a proper amount of anhydrous lithium chloride in a proper amount of a mixed solution of pyridine, triphenyl phosphite and pyrrolidone, adding diamino molecules after complete dissolution, heating and stirring the solution for 12 h, pouring the solution into methanol, filtering and collecting a product, washing with water, and drying to obtain the product PSI; and S4, preparing the PSI / OPBI blended membrane. The blended membrane prepared by the invention has excellent proton conductivity and good mechanical properties, and meets the performance requirements of the proton exchange membrane of the fuel cell; moreover, the raw materials are low in cost and easy to obtain, the synthesis conditions are mature, the yield is high, the feasibility is high, and the application prospect is wide.

The invention provides a preparation method of battery-grade lithium salt, and relates to the technical field of new energy materials. Starting from battery-grade lithium sulfate, part of lithium sulfate is reduced under hydrogen to obtain battery-grade lithium sulfide; part of lithium sulfate reacts with sodium carbonate to obtain battery-grade lithium carbonate, the battery-grade lithium carbonate reacts with hydrochloric acid to obtain lithium chloride, lithium chloride is electrolyzed to obtain metal lithium, and the metal lithium reacts with sulfur, is reduced and is converted into battery-grade lithium sulfide; part of lithium sulfate reacts with sodium hydroxide to obtain battery-grade lithium hydroxide, and then the battery-grade lithium hydroxide reacts with hydrogenation tail gas to obtain battery-grade lithium sulfide. Further, the battery-grade lithium sulfide can be obtained from the lithium-containing ore through the steps of calcination, sulfuric acid leaching, purification and the like. Through conversion and adjustment among different lithium salts, the cost of the lithium sulfide can be adjusted according to different conditions, and low-cost and large-scale mass production of the lithium sulfide is realized.